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FAQs about Temperature and Marine Systems

Related Articles: Marine Water Quality, Maintenance, Coldwater Systems, Heating Marine Systems

Related FAQs: Heating 1, & FAQs on: Rationale, Heating Methods/Gear, Heat Controllers (Fans et al.), Measuring/Thermometers, Heating Troubleshooting/Repairs, Makes/Models by Manufacturer, & Chillers, & FAQs on: Fans For Cooling, Chiller Rationale/Use, Selection, DIY, Installation, Maintenance, Troubleshooting, & Environmental Disease,

Sessile, non-motile invertebrates often suffer the worst for temperature fluctuations. Bugula dentata

Cooling Tank Question   8/10/14
Thank you for the help in advance. I have a 200 gallon reef ready aquarium, with a 40 gallon sump. The tank is set up as a FOWLR. In the sump there is a reef octopus protein skimmer, and a Mag drive return pump.
<What size? Run as a... submersible... source of waste heat>
The tank has a canopy and the people who set it up put class canopies all across the top of the tank (I know that your site advocates open top tanks for gas exchange, but I have left this as such so far to see what the outcome is.
So far, the tank has remained at 79.5. The heater has been turned down dramatically (to approximately 72), and the tank has not dropped in temperature at all. The lights that are used are two 30" LED Marineland Reef Lights. There is also a small LED light in the sump for a small refugium.
<Not much heat from these>
I am trying to get the temp down because I would like to attach my UV sterilizer, but I'm afraid of raising the temperature even further.
<Won't add much... likely half a degree F.>
I have read that Mag Drive pumps are notorious for this.
<There are other brands... My fave: Eheim>
I would also like to avoid buying a chiller for a tank that has no coral lighting needs. I opened two of the glass tops for about 7 hours, and it really didn't make a difference, but I didn't take them completely off, and there is still a canopy that retains the humidity. Should I just take off the glass tops entirely?
<IF the water as vapor won't cause trouble/s, nor removal allow livestock to leave>
Should I put a fan in the area underneath the tank to help with evaporation down there?
<Worth trying>
Or should I just get an external pump?
<Is what I would do... Eheim>
Also, I should mention that I keep my house temp at around 75 at all times in the summer. Thank you so much, Mike
<Welcome. Bob Fenner>

Arctica Chiller problems - 3/10/12
Do you know how I change the chiller temp from C to F

<Isn't it 5/9 F minus 32 or going the other way... 9/5 C plus 32... B>
Frank Zoche
Re: Arctica Chiller problems    3/12/12

I mean the chiller display - is showing C as the temp on the display. I want to switch it to F. Can not find it in any of the internet PFD owners Manuals
<? I'd write JBJ re their products: http://www.jbjchillers.com/
or just do the conversion as I've replied already. BobF>

Can't stand the heat!  5/8/11
Hi Guys,
I want to again thank you all for being so kind and helpful. Without you I don't think I could even be a little successful in this hobby! Not that I am doing so great anyway!
SO here is my situation. I wrote a couple of days ago because I have had to basically tear down my 54 gallon corner bowfront tank because it crashed and burned for some unknown reason.
<There are... such mysterious wipe-out syndromes>
Water quality was all good. I didn't have any failures and I have no idea what happened except perhaps some contamination issue that I was unaware of. I mean within a 3 week period of time all my fish and all my inverts were dead with the inverts going first.
I decided to go nuclear in this situation because I don't want to chase my tail so I am staring over. I beached all my live rock (sad cause there were some nice things on it) then thoroughly let it dry for a week and rinsed it in RO water real well with de-chlorinator in it, then let it dry out for another week. I changed out all the substrate to 40 of Sea-Flor with 40 lbs of Carib Sea Live Sand on top of that. I put the rock back in (about 60 lbs left room for new rock when I buy corals eventually). I bought RO water and mixed the salt myself with Instant Ocean Reef Crystals to a s.g. of 1.021.
<Mmm, I'd keep spg higher. See WWM re rationale>
I replaced three Maxi-jet 1200 powerheads running in the tank on a maxi-jet wave maker. Two of the powerheads have new Hydor Flo rotating deflectors on them. In addition I have a Remora-C Pro Protein Skimmer running with a Mag-3 pump (brand new, the old one was starting to give me problems). I had a 250W Hydor submersible heater I was reusing set at 78 F.I had a Coralife digital thermometer that I replaced because it did not stay where I put it.
So I got a new Lifeguard Large Digital Thermometer because it had the ability to set alerts which I thought would be a good feature to have as a back up. I have a glass canopy on the tank. For lighting I have a 24" Current Outer Orbit fixture (apparently discontinued) with 1- XM HQI 150W 10000K MH, 2- 24" 40W T-5 VHO Actinic White (50% 420nm and 50% triband phosphors. 12000K) and 2 - 24" 40W T-5 VHO Super Actinic 420nm bulbs. All the T-5 bulbs are brand new and for UV Fluorescent. The light fixture is hung from the ceiling. Previously it was hung 4 inches from the glass but I was having and algae problem so you folks recommended I raise the fixture to 8 inches which I did and where it is now and to decrease the time it was on.
I was running the MH 12 hours. I currently have the lights set up as follows. The T-5s come on at 10:00 AM, followed by the MH which comes on at noon. the MH goes off at 8:00 PM, followed by the T-5s which go off at 10:00 PM, My night LEDs (6 - 3W white and 6 - 3W blue) are on from 9:00 PM until 11:00 AM. I used this configuration to optimize the lighting for when we are home to look at the tank but trying to be close to a natural summer light cycle.
So once this was set up I needed to seed the tank so I decided to go buy some live rock to add.
<... the spg...>
I found a couple of small pieces (about 2 pounds worth that had a really nice sponge on it and some green Zoanthids and another piece had red coraline algae and the last piece I found some amphipods on so I got those and plan to perhaps get some more or maybe a single fish and give it all a while. I am not in a hurry at all. So I think I am doing pretty well at this point. Then I notice my tank temp is around 86 degrees (this is before I ever turned any lights on the first time. I notice the heater is stuck on so I pull it out and toss it in the trash.
So I started doing research here on WWM to figure out what heater to buy but noticed most of the info was a few years old so I actually wrote you last week about revisiting what heater brand was most reliable and what wattage to go with if I went with two heaters in this tank instead of a single one.
You guys must be swamped because I had not heard back yet (I understand completely!)
<We answer all w/in a day almost always. Perhaps your message was "lost in space">
Anyway while I am waiting to hear back I expect the temp to drop so I start running my lights as described above and I bump up the thermostat in my house to about 78 F. I can live with it even though I like it a little cooler. Well my thermometer continues to range around 86 dropping off a little in the morning and creeping up a little in the evening. I figured I had a bad thermometer because previously my heater had to work to keep the tank at 78-80 F. I bought two inexpensive glass thermometers and put them in and they to say the tank is at about 86F.
I am at a loss? Any ideas what to do or why its running so hot now when it didn't before?
<Best to unplug one electrical item at a time; one per day... and see if this makes a difference. Could be a pump, the lighting...>
I can't really afford a chiller or the electric bill that would go with it. Any help you can offer would be great!!! Info on heaters would be helpful to in case I need one at some point.
Also since the tank is so new and I am restarting it and basically have whatever was in the live sand and on those few little pieces of rock I bought I figured I should feed the sponge and coral. I am using PhytoChrom by Brightwell Aquatics with the targeted feeding method per the directions.
Thoughts? Good product? Will it do the job? Anything to look out for? How often should I feed them?
<At most every other day. Am not a fan of such phytoplankton products by and large... "Size matters" and more re the utility of such "foods". IF this or any of them work for you, fine>
Thank you so much for all your time and all the help you provide to all of us.
<Welcome. Bob Fenner>

Temperature spike 6/25/10
Hi Crew,
Sorry to be a nervous wreck, but I'm still pretty new to the aquarium game, having set up my first tank up around 9 months ago
I got home tonight after work to find that there was a dead peppermint shrimp on my substrate. I checked parameters and found that the temperature had risen to over 86 degrees (I think due to the heat outside).
<Does it have a sump? Some kind of fan's should be installed to aid in evaporative cooling.>
Everyone seems to be OK at the moment, and so I have opened the hood and turned off some of the lights to try and cool the tank a little. Should I do anything else to try and cool it quicker, or would a quick drop in temperature be worse than the excessive heat present at the moment?
<Getting it back to temperature quick is a good idea. At what temperature do you normally run your tank? Try to get it down to 80ish with some ice-cubes in a Ziploc.>
My other inhabitants are a pair of ocellaris clowns, a Lemonpeel angel, a Firefish and a chalk goby, plus some cleaner shrimp and snails. Do you think a temperature spike will have any long term affects on these guys?
<It will have caused stress, so disease may occur. Keep a close eye on the tank. Check parameters frequently and keep water quality pristine. Figure out a lighting schedule which will keep the tank below 80. Add a chiller,
cooling fans, or turn up your AC.>
I feel like such an idiot.
<Don't, it's a common occurrence. Just take corrective action.>
Thanks for your help,
Dave - Portsmouth.
<Scott T.>

Re: Temperature spike 6/26/10
Hi Scott,
Thank you so much for your help. Bob's book and this website have been so useful in making sure I haven't messed up too often during the set up of my tank. It really is an amazing hobby and you guys have made it all the more enjoyable.
Glad to say the temperature is back at 80 for now and I have ordered some cooling fans to keep it there. All parameters seem to be normal and all inhabitants healthy for now.
<Thank you, and great to hear!>
Thanks again
<Glad we could help, Scott T.>

Re: Sailfin Tang Compatibility, now sys. temp., spg.  -- 12/01/09
two last questions - what is a good temp for the water in the tank - mine now is at 82-84. I cant seem to get it adjusted to 82, its either 86 or way to cold at 76.
<Optimum for reef inhabitants is 76-82 -- I tend to hover around 78-79 on my tanks.>
And while your answer about my problems with the Sailfin tang - what do you suggest for a good salt level? I've kept mine between 19 and 21 seems like the fish like that - well I guess except for the Tang :(
<Do you mean 1.019 and 1.021? This is too low -- aim for 1.026.>
Once again, thank you for all the helpful information - we can read and read and try and try - but its always nice to have someone answer the weird questions.
<Absolutely, we're glad to help!>
Hope you have a WONDERFUL holiday season.
<Same for you and yours, Cecilia.>
Cecilia Lester

Aquariums temperature variance 11/11/08 <Hi Jeff> I was wondering how much variance in temperature is within a safe margin for my reef tank. My tanks seem to very between 77 and 79.5 Fahrenheit. Is this enough to cause stress? <As long as this is within a 24 hour period, you should have no problems.> Thanks very much for the valuable information you folks make available here. <You're welcome. James (Salty Dog)> Jeff

Trickle Systems 11/11/08 I am quoting an aquarium tank line and am having a problem figuring out an answer to finish the quote. One of the tanks will be pumping 9000 GPH through a trickle system at 82 Deg F and we need to figure out the heat loss in the tank. Any suggestions? Thanks, Dan <Dan, temperature loss will be dependent on multiple factors: surface area/volume ratio, difference between room and tank temperature, rate of evaporation, and so on. In other words, you can't make a guess. You'll need to experiment! If it's any help, I'd recommend going with two or more heaters that provide sufficient wattage for the system. Multiple heaters avoids the problem of "sticking" (where one heater sticks on and boils the fish) and "chilling" (where one heater fails). If the room is substantially colder than the tank, increase the wattage a little to compensate. Otherwise you should be fine with the standard wattage. Cheers, Neale.>

reef temperature 5/23/08 Hey Crew, Well, I'm going to be ordering my chiller within a week or so, and I'm wondering what exactly is the perfect temperature for a reef. This article from Drs. Foster and Smith says that the average temp. on the reefs is 82F, but that a tank should be 72-78F (http://www.drsfostersmith.com/pic/article.cfm?c=3578&articleid=1079&category=582). Can you please explain. What would be the ideal average temperature? <I'm not sure why Drs. F&S make this recommendation. They're a great online vendor and I've bought from them several times. However, when it comes to general advice on animal/aquarium care, I wouldn't consider them a reliable source. I've seen a lot of the advice they give and *some* of it is just wrong. Anyway, when it comes to aquarium temperatures, it depends on what animals you are keeping. For reef tanks, I'd suggest you keep the temp. close to that of the wild reefs (80 to 82F).> Thanks In Advance, Random Aquarist <Best, Sara M.>

Tank temperature, Too Warm... Bring Down Gradually with Chiller.   3/2/07 Dear Bob, <Hi Jason, Mich here.> I have a 55-gallon reef tank that has a typical temperature of 85 degrees.   <It's getting hot in here!> I bought a chiller to reduce the temperature as well as protect the tank when we lose power from hurricanes. <A wise investment.  Do you have a back up generator?> I have a bubble tip anemone with some feather dusters, yellow tang, 2  percula, 1 tomato clown, coral beauty angel, brittle star, flame scallop, urchin  and some gobies. <Oh buoy!  Watch that anemone, can cause big problems.  The yellow tang should really be kept in something over 75 gallons.  The flame scallop (Lima scabra) needs a large supply of plankton in order to survive...is best to culture your own.>   I don't want to reduce the temperature and hurt anything but I also know the temperature I have now is too high. <Yes.  If the temperature has been consistently this warm, I would bring the temp down very gradually over several days.> Thanks for all your knowledge and help <Welcome!  -Mich> Jason

Fluorescent to MH blues... too much heat, vacillation in temperature in a SW 55 Hello all, I just purchased a new light for my 55 gallon reef tank. I went from a compact fluorescent which was about 130watts total to a metal halide system. I wanted to be able to get some of the cool corals. I already have a few corals and they seemed to be doing alright with the other light but figured they would love the new light. The new light is a Current USA Outer Orbit fixture 48”. It has 1x150W 10K HQI-MH 1/ 2x130W Dual Actinic & 6 Lunar Lights. I Have it mounted almost 13” over the tank. The problem that I’m having is that the temperature in my tank has sky rocketed. It’s usually 76-78 and since I have added the light it’s gone up to 86 which I know is on the high end. The fish and the corals seem to be doing alright but I don’t know what the long term effect will be. I keep the AC in the house set at 70 and I still can’t get the temperature down below 81. When the light comes on the temperature climbs to 86 before the light goes out. Is the light too much for a 55 gallon tank? <As it is, yes... you have too much thermal fluctuation for health and safety's sakes> I’ve looked into chillers and they're so expensive. The light cost a fortune. Is there anything that I can do to get the temperature down? <A few things... evaporative cooling by supplying fan/s to blow air across the surface would help... elevating the light even more over the tank... adding more volume... in a BIG sump/refugium elsewhere, that's tied in with the 55...> What’s the long term effect? <Shortened life-spans for your livestock, big electrical bills... all that goes along with these> Set up is a 55 gallon tank set up in December 2004. Filtration - Eheim Professional II Canister filter up to 92 gallons. Protein Skimmer - Aqua C Remora with Mag Drive Power heads - 2-600, 1 1200 Maxi Jet, 1 Zoo Med Power sweep 228 Heating System - Hydor Eth 300 External Thermal heater 75 pounds of Fiji Live Rock, 60 LBS of Fiji Pink Aragonite Live Sand. Kent Marine Maxxima 35 Hi-S R/O / Deionizer 4 Stage Reverse Osmosis Unit. Current USA Outer Orbit Fixture – 48” 1x150W 10K HQI-MH 1/ 2x130W Dual Actinic & 6 Lunar Lights Inhabitants – 1. Purple Tang 1. Blue Damsel 1. True & 1 False Percula 1. Lawnmower Blenny 1. Dottyback Fridmani 1. Diamond Goby 1. Branch Coral - Paralemnalia or Lemnalia Tree Corals, Finger Leather, Branch, or Cauliflower Corals 1. Red Feather Star 1. Torch Coral – (Brown) Large Polyp Stony 1. Red Star Fish Misc. Hermit Crabs Misc. Snails <Bob Fenner>

Temperature Swings and Algae Things (New Tank Breaking In> Hiya Bob or whoever is sitting in today, <Howzit? Scott F. here today!> My tank has been circulating and in operation for about 5 months, the lights were only switched on for the first time about 4 weeks ago, only a number of Chromis in the tank when they got switched on. The tank is 9'x2'x2', about 320g including sump and refugium (which isn't populated yet), with what can only be described as an abundance of lights, 4x400w MH and 4x60w actinics. <Sounds great!> Originally I was going for an SPS setup but my tastes have changed and primarily I will be going for stonies, mushrooms and zoanthids. <I am a big fan of some of the LPS corals, myself, such as Faviids. Maybe not as "trendy" as the SPS corals, but every bit as pretty and interesting, IMO!> So my lighting needs have definitely reduced, although I would like to keep clams. <An interesting mix.> The problem I had is soon after switching on the lights, I had to go away for 2.5 weeks with work. My girlfriend kept an eye on the tank, and I had a man from the LFS who helped set it up come round once a week. <Good!> When I returned, I had a serious algae problem. The front of the glass had been cleaned by the LFS guy, but there were filamentous algae growth in nice bunches over various parts of the tank, and the back screen had almost a total cover of it that looked like it could be peeled away. <Unfortunately, this is a very common occurrence in new systems, which are rich in nutrients and short on mature nutrient export systems.> I went to the LFS and bought a load of snails and hermit crabs (I did have a small number of both of these already), and also got myself the first of my real fish, 4x Yellow Tangs. These were preplanned and not an impulse buy and it seemed like a good time to get the algae eaters in. <It is. However, I'd like to think that you'll embrace a quarantine procedure in the future with all new fish, particularly Tangs, which are notoriously susceptible to parasitic infections.> Upon return I discovered my second problem, the temperature  outside was about as hot as it gets in England, about 31C, and my tank temperature was up to 29C. This I found out as I was letting my Yellow Tangs acclimate in their bags. (As the tank was empty bar the Chromis and cleanup crew I didn't quarantine) <Still a good idea, as you don't want new fish to bring potentially infectious diseases into this new tank...> Immediately turned off the lights and went outside to check if the chiller was working, it was, but I guess the poor thing was struggling with it being so hot outside. <Understandable!> Next day, the Tangs seemed to be fine, the cleanup crew were getting around and nothing seemed the worse for wear. <Good to hear.> I changed the lighting period to switch on later than usual, bringing the lighting period to start as the sun is setting, and hence colder outside to give the chiller a better chance. This didn't seem to make much of a difference, as for the last hour or so of the 12 hour main lights lighting period my temperature had once again hit 29C. Fortunately, there is little in the tank to get stressed over this, and the Tangs are coping far better than I thought they would. I have read from Eric Borneman's book that temperatures on the reefs can exceed this. <Yes, but it's not a good idea for extended periods of time, of course.> But I bet the swings were not so high overnight. <Correct, in most cases, although some lagoons and reef flats affected by tidal changes do have such fluctuations.> I have read on your site that swings of over 4F are to be avoided. <Ideally, yes.> Is this definitely a big problem that I need to sort out or can I allow the tank to take a nearly 5F swing almost everyday? <Well, it's not an ideal situation on a daily basis, so you will most likely want to make some hardware changes to cope with this fluctuation in temperature.> I assume not and see 3 potential solutions to the heating issue: 1> Change the lights, as stated, it is a lot of lights for the system and probably should be reduced. <Certainly will save on energy costs, but you have to make sure that your future plans for this system will not require such high intensity lighting, or you'll be in for frustration!> 2> Add a second chiller outside inline with the first to maybe kick in at about 0.5C higher than the first. <A functional idea, but it may be better to simply invest in a more powerful chiller and just have one.> 3> Redrill the lighting fitting to have the lights sit another few inches above their current location. <Again, another potentially viable idea.> Any thoughts on which I should use or definitely shouldn't use? <Personally, I like the idea of cutting back on the lighting (if that works for you), and perhaps a more powerful chiller. Additionally, you may want to blow a fan or two directly into the sump, for evaporative cooling to occur.> Also my algae problem is real bad, I am going to trim back as much of it as I can for now, and I have no idea where the nutrients for its growth have come from. <Lots of possibilities: Source water, material in the rocks and substrate, even salt mix or carbon! Do investigate.> Once it is pretty close to the rocks I am going to see how well my Tangs can handle the situation. <Hopefully, they can make a measurable impact.> Any ideas on algae control or do you think I should be ok with what my current course of action is? <I would look into the possibilities outlined above. As stated previously, such algae outbreaks are common in new systems, so don't be discouraged. Continue to manage nutrient export processes (i.e.; aggressive protein skimming, water changes with good-quality source water (RO/DI), careful feeding, general good husbandry habits, and a healthy dose of patience! You can and will get through this phase if you think along those lines.> Sorry for the lengthy email but I wanted to set the scene a little first. <No apology needed; you did a great job!> Thanks in advance, Gary <Best of luck to you, Gary! Hang in there! Regards, Scott F.>

Tank Overheating - 06/13/05 Hi! <<Hello!>> It is miserably hot at the moment in Montreal (no joke, it can be hot in Canada too).  My tank's temperature is peaking at 30C since a week. <<Okay, for my/our readers use that converts to 86F.  This temperature is higher than I would recommend someone to keep their tank, but not really "out of bounds" if kept consistent.>> I just bought 130lbs of Fiji LR a month ago.  For now that's all there is in the tank with a baby ocellaris and a wormfish (magnifica).  I am already running a fan over the tank and within a week I am getting air conditioning (ouf!). <<Wonderful stuff that air conditioning...of course I live in the sultry Southeast.>> Is the LR/micro fauna endangered by such temperatures (30C)?  I am freaking to think the LR may be "damaged" (it was a big investment) and also worried about the friendly fishes.  Should I really be worried? <<If you're "peaking" at 30C and dropping no more than a couple degrees at night I think you'll be fine for now.  The elevated temperature will get everyone's metabolisms running, but if you ensure good water flow and oxygenation your rock and critters should make it without any permanent damage.  And keep in mind your rock was collected from very shallow waters that get "very warm" under the hot tropical sun...even totally exposed at times during low tide...little concern here, really.  But if you want to go to the trouble, fill a couple 2L soda bottles about half full of water and freeze 'em.  Then during the hottest part of the day float the frozen bottles in the tank to help keep the temperature down.  If that's not practical for you then add another fan to blow across the surface of the water.  You can also set the timer on your lights to shut off during the hottest part of the day; it won't hurt to do this until you get your conditioned air.  At any rate, I think all will be fine until the air conditioning kicks in.>> Thanks! Dominique <<Welcome, Eric R. (currently sweltering in 90+ temps and humidity himself)>> Water temp. 06/11/05 Hi, first just want to say that I love your site. <<Thanks a bunch :)>>I'm having a water temperature problem. Background: 75 gallon FOWLR, about 100 lbs. live rock, 2 clowns, 1 blue tang, 1 yellow clown goby, 1 scooter blenny, 1 emerald crab, several snails and hermit crabs, one anemone, one mushroom. We've had the tank for about 1 year, and recently upgraded to metal halide lamps in order to hopefully start getting some corals. They are mounted on top of the canopy about 8 inches away from the top of the tank. Even before the metals, the tank was never below 80-81 degrees (with about 200 watts of fluorescents), but now its up to 85ish in the daytime. At night it doesn't go below 81. I'm worried that this is too hot. We live in South Carolina, and keep our house as cool as possible, and the tank isn't by the window. Yesterday we hooked up a fan to blow between the lights and the tank, but this today, the water is still warm. By the way, we try to keep the lights on for 13-14 hours a day. Is this too long maybe?   << I would try the MHs for 8 to 9 hours.  The corals that you are keeping do not require that long of a light cycle so I would shorten the MHs to 8 hours and leave the actinics where they are at.  Also try having a fan blow across the top of the water. You do not have the glass lid on top right? >> Is there some way to keep the water cooler? Thanks a lot for your help. I hope I've provided enough info. Tait <<Thanks for all your support :) EricS >>

Water temperature 06/08/05 I'm having some problems with temperature in my salt water tank now that the hot weather has come.  I have a ceiling fan on in the room and windows open and tank lights off.   The tank temperature seems to stay around 87 F.  I would like to know if there's anyway to cool the tank down or is there just nothing I can do? << You can setup a small computer fan to blow across the top of the water.  A sump is a great addition too because it helps to naturally cool the tank.  Some people have taken plastic zip-lock bags, filled them with ice and floated the bag in the tank. Good luck EricS>>

- Tank Temperature Too High? - Hello, I have a 39G FO tank with one Cleaner Shrimp. The room that it is in is hot in the summer, and moving it to another room is impossible. Anyway the tank seems to be holding at about 86F. Is this too hot? <Well... it's on the high side of what is sustainable, and considering that summer is isn't here yet, you're going to run into problems if you don't try and bring that temperature down.> If so what would you recommend to try to lower the temperature short of buying a chiller? <A fan blowing across the surface of the water will help.> Also I plan to get live rock and corals, etc.... in the near future if this temp is ok for the fish will it ok for corals? <Will accelerate their metabolism and will result in shorter life spans. In the case of the corals, almost certainly you will need to get that temperature down by six degrees or more unless you only want to keep them for a couple of weeks to months.> Thanks BTW I have a Current-USA Lunar Aqualight. <Cheers, J -- >

Temperature Problem I have a newly cycled 100g corner FOWLR tank with 1 Yellow Tang, 1 Hippo Tang, and 2 Yellowtail Blue Damsels. I'm using power compacts lights. The temperature is 79.5 during the day with the lights off and 82 at night with the lights on. The lights are on for 5 hours each night. The heater is set to 77 and never comes on. I just added a fan and it did not help. It seems like the lights are doing all the heating and I can't bring it down. I also just started using my protein skimmer. Does this increase the heat? My fish seem non affected. Please help.  <Is this a wood canopy you have your lights and fan mounted in? Pumps will increase the temperature of the tank slightly. You might try blowing the air from the fan across the water and see if that helps you. James (Salty Dog)>

Making a tank quieter and cooler Hello. I have two questions that are related. Let me start by describing my current setup. I have a 135 gallon reef aquarium with a 30 gallon sump. It is six feet long with 4 VHO lights (kept about 3 inches above the glass) and is used as a room partition with dedicated outlets in the cabinet under the tank. I had a custom cabinet built with the air vents on the 4 doors below, on both sides. I have a single return that is powered by a Mag 9.5 pump. In addition to the return pump, in the sump I have a Aqua Medic Turboflotor protein skimmer powered by a Rio pump and also a smaller 200 gph Rio pump for more power through the skimmer. Finally I have a drop-in 1/4 HP Delta chiller with the coil placed in the sump. The tank is doing great. I moved into an a/c apartment about 1 ? ago, which we keep about 68-72 degrees. Even in the winter my tank runs hot. The chiller is set to run when the temperature of the water is 77 degrees and it seems to be running 4-6 hours a day, mostly when the lights are on (which is around 11 hours per day). Without the chiller on, the tank will go to 84 plus degrees during the day and come down to around only 82 degrees at night.  <Your chiller probably needs a Freon charge. They work similar to an A/C.> Question 1: My wife complains about the noise since the tank is right in the middle of the living room/den. Any way that I can make the setup quieter?  <I have never read in any marine book, the word "wife". It's not part of the aquarium system mind you:) OK, lining the interior of the stand with 1/2 insulating foam is a start. As for the vent holes in the doors, I can't help you since I'm sure it would have to have aesthetic value (wife again). Putting the pumps on insulating foam helps also.> Question 2: The chiller seems to be not performing well. I bought it about 3 years ago. I try to keep the water at about 77-79 degrees. Over the past couple of months, I have seen the tank go to 82 plus degrees and hear the chiller running but the coil is not very cold. (The grills are kept fairly clean and clear.) If I play with the chiller (jiggle the adjustable coil hose or turn the chiller off and back on) it seems to kick in better. With summer approaching I am getting nervous. Any ideas what I can do to cool the tank? Should I buy a new cooler that might work better? Is there a chiller out there that would also make the tank a little quieter.  <As above, have Freon level checked by an A/C guy. As for heat, I'm thinking you have a custom hood also. If you don't have one, I would put an exhaust fan in the hood somewhere to exhaust the warm air. James (Salty Dog) Merely joking about the wife bit, felt like adding a little humor to my day. I have one of those species also.> Thank you for your help. David 

Water temperature for my FOWLR angelfish tank Good Afternoon, I have a 125 gal FOWLR tank. 1 5 inch Imperator & 1 7 inch Blue Faced Angel. I just added a 36 watt UV on the tank with a pump for it in my wet/dry. The temperature of my water is 83 degrees. Do I need a chiller? I was told that Angels like warmer water, but will that do harm long term???  <Should be fine... will slightly shorten lifespans, could cause trouble in terms of gas solubility... in the event of power outage, overfeeding, die-off... Bob Fenner>

Hammer coral question Hello WWM Crew, I am very new to this hobby and have learned so much from you! (I need to apologize upfront for my run-on paragraphs - my kids spilled on my laptop and the Return key does not work-he..he..). <Yikes... do either take it apart or have someone show you how to do this... can be cleaned, dried...> I have a 75 gal reef tank that just cycled. I bought 7 Turbos, 5 hermits, and 2 scarlet cleaner shrimp from my LFS about a week ago (after cycle) for a green algae problem. All my water parameters are fine (78 degrees; pH 8.2; 0 on Ammo., NO2, NO3; Alk-Normal; Calcium-460) so my LFS said I could add a Hammer Coral and pair of Percula at the same time. Everything was fine until yesterday. I added a 3rd Powerhead (CAP 800) the day before, and while positioning it, it blew some sugar fine sand all over-including a little on the Hammer. It seemed fine, but yesterday half of it retracted into its base and now all of it is retracted. Was it the sand? <Very likely yes> I am wondering if the current is bothering it now? <Not if it is not too brisk, direct> I adjusted the temp cooler for the algae problem and now the temp of the tank fluctuates from 77-82 when the two   250watt 14KMH lights are on - Is that a problem? <Mmm, yes... five degrees is a bit much... three is acceptable diurnally... you'd do well to look into fans for cooling the tank while the lights are on. To say this in another way, the daily temperature shift is likely adding too much stress> The Hammer is sitting on the sand for now, so I was wondering if I should pick it up and gently shake it to get the sand out, leave it alone, or what?  <Leave it alone... Has mechanisms for "dusting itself off"> Also, I plan to get a jawfish and watchman goby eventually, so I'd like to move the Hammer from the sand to a ledge. How high should I put it and how much current? Thank you in advance for your advice! -Stellaboom <Wait a good month before touching the Euphyllia, can be positioned about midway in depth here. Medium to low water current. Bob Fenner>

Re: Hammer coral question and "The Pepsi Syndrome", temperature variation Thank you Bob for your input! I just purchased your book and am looking forward to reading it and learning more (especially on Refugiums - I set one up based on WWM's and LFS's advice, but still am a little in the dark about it (me.... the refugium light is on 24/7 <g>). The Hammer coral has half of it's polyps out today (better than yesterday).  <Ah, good> I do have 2 4" fans with heat sensors mounted on the back of my hood, and they run non-stop when the lights are on. <Mmm> I was thinking about adding another fan over the sump (30gal sump/refugium) inside the stand. <Good idea... if not... perhaps changing, shifting your light cycle to later on in the day, more off when the room is warmer... will bring the temp. shift down a couple of degrees> I didn't have the large temp fluctuation when I had it set at 80 deg.  Should I try the sump fan first or would I be better to just leave it set higher?  <It would if this was the only practical means of reducing the variance> If so, any other suggestions for the hair algae? (which is still out of control) more Turbos? Lawnmower Blenny? Wait it out?  <Actually, perhaps "all of the above"... and more. Do take the long read on WetWebMedia.com re algae control> Thanks again! PS. Laptop will be going into the shop for a cleaning and overhaul soon-that's what I get for letting my 5 yr old twins play Spongebob on it (I was only trying to "enhance their appreciation of the living world" and the love of all sea creatures-hee :) <Heeee! I had friends spill a Seven-Up on mine on a live-aboard on the Red Sea once! What a sticky mess... but luckily the camera rinse tank was stocked with... Bottled water! So, rinsed the keys over and over... dried them, re-installed... and luckily no problems. Bob Fenner>

Re: Temperature Fluctuations Hi Bob, <Walt> Thanks again for the response. I took your advice and returned my heater. It was only a month old and I still had the receipt so they refunded my money no problem. <Great> I tried in vain to locate a Eheim Ebo Jager heater but to no avail. <Strange... should be available from online etailers... Ken Wong/Marine Depot, Bayside distributes Eheim in the U.S.... they must list them. Wow, actually, they don't! In fact, I don't see them listed by anyone... must be a demand/request of the manufacturer... now owned by Eheim... which ARE sold by discounters...> I did a bunch of "consumer review" searches on-line and found consistent positive reviews for the Aquarium Systems (Marineland) Visi-Therm heaters. <Ah, yes, also fine products> My local pet store stocks them so I went and bought a 250 watt unit. It held the temperature to within one degree overnight and that is saying something as it was very cold up here in upstate NY. Have you had any experience with the Visi-Therm models? Thanks again. Sincerely, Walt <Yes, a great deal... have even been to Italy where they're made... Bob Fenner> 

Temperature Crisis Hi, You have been very helpful in the past and I would appreciate some help again with bringing down the temperature in my tank. I have a 75 gallon Tenecor "simplicity" plus. It started off simple, then I added a protein skimmer, UV sterilizer (both in a very overcrowded sump area) and a Seio pump in the main part of the tank to increase circulation. I also removed the bio-balls and added live rock and filled that area.  I believe that as result of these add-ons/modifications have increased temperature in the tank. It's now hovering at around 86 degrees. I thought maybe something was wrong with the heater sensor so I unplugged the heater 5 days ago and no improvement.  Any suggestions on how to bring down the temperature? I really don't want to have to buy a chiller.  I've been thinking about putting the UV light on a timer and running it only 8 hours a day. I'm not sure how much that would reduce the benefits of the UV or how much that would bring down the temperature.  Also, would this temperature have hurt my live rock or any other living critters that I can't see?  <UV's aren't much different than heaters. If you have a 16 watt UV for example, then you have a 16 watt heater also. Eighty Six degrees is not a good temp for any marine animals that we keep. I'm thinking your lighting is also contributing to the high temp. If not already using, you definitely need a cooling fan in your hood also. As far as UV benefits, I personally do not like them. They kill what we are trying to produce in our live rock, such as pods etc. Whatever goes through them, good or bad is zapped. James (Salty Dog)>

Can the sand bed be a different temp. from the rest of the tank? Hi Adam, < Hello Narayan. >  Hope all is well at your end. My reef tank has been running pretty well so far... Unfortunately I can't say the same for the newly set up refugium. What a pain to work on an under tank refugium. So, last week I tore it down and re-set it up on the floor next to the display -doesn't look as neat, but way easier to work on, plus all my aquarium maintenance stuff can go back under the display.  < If you don't mind the look of it on the floor, good idea. >  I have two thermometer strips glued on to the glass sides of the refugium, one near the bottom of the 6" DSB and the other in the middle of the water column. The water temp is 79F, but the bottom of the DSB is at 71F.  < I don't believe it. I don't believe they can be that far off. I'd get a regular thermometer. > <<I do believe it... a simple experiment/demonstration will convince you. RMF>> Should I be concerned about the refugium's DSB's temperature? The DSB in the display is 4.5" and is at the same temp as the rest of the tank.  < Just thinking of how well water transfers heat, I can't believe it has the kind variance in a tank. Here is what I would do. I'd go to Radio Shack and buy a digital thermometer. They are under $10 and fun to play with. Then I'd move that probe up and down in the water and see what it is says. > Thank You, Narayan < Blundell >

Can the sand bed be a different temp from the rest of the tank? continued But Adam, There is very little water movement in the sand bed... I can actually feel the difference with my hand against the glass. The water is noticeably warmer than the sand near the bottom.  < This just doesn't sound right. I guess it could happen, but the way glass conducts (transfers) heat I wouldn't think it would have a difference you could feel. I guess I was wrong. >  And, I'll go get the radio shack thermometer to try... The thermometer strips are on the outside of the glass and it is cold here in Rhode Island, especially near the floor, since the tank sits on top of a inch of carpeting on a concrete slab.  < I still think the digital thermometer will be a good addition. ><<As a side note, input, there are indeed some very large differences in temperature through aquarium substrates at times... for "European" aquarists (and others) the rationale for using heater cables, situated in/under the substrate... heat rises... RMF>> Thanks, Narayan

Overheating Tank. 12/31/04 First I want to thank you for all your advice. I've been reading posts on WWM about tank cooling and I noticed you are not a big fan of chillers.  Well I went against your advice and bought one. Well I soon took it back after my wife yelled about all the noise. <Ha!  My wife hates chiller noise as well.  I think the best way to characterize our general feelings about chillers is that they should be a last resort.  They use a lot of energy and make a lot of noise.  If you can control heat without them, great!> I have a 40 gal reef with a 30 gal sump/refugium. I have a Turboflotor skimmer (which works wonderful thanks to your advice about the needle wheel). An Eheim 1060 returns water to the tank and feeds the skimmer. I have two mag 9.5 pumps in line on a closed loop and 570 watts of VHO in the hood. In the hood I followed your advice about fans. I now have 3 -3in ice cap fans and the tank still goes up to 81.7 degrees by the end of the day. <I don't think you have problem.  I would consider 84 to be a reasonable upper limit.  It is much more important to avoid spikes in temperature more than a few degrees above the normal daily high.  For example, in your case, I would only worry if the temp jumped up to 86.> I also have a 4 in fan in the cabinet where the sump is located.  I have no more room for additional fans not to mention 3 fans is a bit noisy. Any suggestions would be appreciated. <Submersible pumps (even when used in-line) add a lot of heat to the water.  If you were to replace your mag 9.5's with a single Iwaki pump, it would probably bring your tank temp down by a couple of degrees.  Make sure that your fan placement is optimized to move the maximum amount of air.  If they are arranged to blow in one end and out the other, it move a lot more air than if they all blow in or all blow out.  Other, less conventional options include a geothermal system using well water, water from a basement sump or buried tubing to expel heat to the ground, or a home-made chiller using a dormitory refrigerator.  Hope this helps.  AdamC.>

Questions on temperatures - 11/17/04 Hi guys. First like to thank you for the great site, I have been finding so much info here. <Excellent. Tis our modus operandi!> But I do have a question. I have had my saltwater tank going for 87 days now. <2 and a half months is still quite a new tank in my opinion.> 45 Gallon tank, 44 lbs. Live Rock, (2) AquaClear 200, (2) Powerhead 402, Red Sea Prizm Protein Skimmer, 30lbs. Seeded Aragonite powdered sand, 40lbs. Crushed Coral Substrate. <The sand is underneath the crushed coral? Not necessary to do this> (2) 30W Aqua Glo "12 hours/day" (2) 10000K Blues "14 hours/day" Livestock: (1) Bianni Cardinal, <Banggai??> (2) Pajama Cardinals, (1) Scopas Tang, (2) Clownfish "Percula", (1) Dwarf Lionfish, (1) Coris Wrasse <Too many fish for this small a set-up The cardinals are a good choice, the clownfish is likely fine, the Scopas, the Lionfish, and the Coris concern me. This a quite mis-understood fish. The usually range in size but if I were you, I would positively identify my fish and do some research on their size and habitat. I think you will be shocked.> (4) Electric Blue Hermits, (1) Scarlet Red Hermit, (1) Electric Orange Hermit, (2) Mithrax Crabs (1) Pineapple Brain Coral, (1) Xenia Pulsing Coral Temp: 25, <77 Fahrenheit> pH: 8.3,  Ammonia 0.0.,  Nitrite 0.0,  Nitrate 0.0 ,Phosphate 0.1,  Gravity 1.025,  kH: 13 dKH,  Cu 0.0,  Ca 440 I do regular maintenance every week, having got my brown algae under control. <Excellent to hear!!! This the proper way to start out. Good on ya, mate!> My question is this.  I have read that many reef keepers are keeping their tanks between 80-85 degrees.  What are the pros and cons of keeping my tank this warm? <Well, I would rather state, in my opinion, having traveled to quite a few tropical locales and have been diving in various tropical regions, I would be more concerned with the average of low and high water temps as it relates to reef keeping. Do some research after positively identifying you inhabitants, look at their region, there should be some info on the average temps of their location. Then adjust your tank. I personally prefer the average of 77-80. My tanks do tend to fluctuate in temp as lights tend to warm the water a bit. Plus summer temps tend to also help my water to warm. So you may need do some adjusting or add a chiller or something of that magnitude.>  Do corals prefer a warmer tank? <74-84 is, in my opinion considered extreme ends of the spectrum when it comes to most corals> And do you think my lighting schedule is ok? <Should be OK. Watch the corals. For pulsing Xenia it is likely enough light but I think the Pineapple coral will likely need more powerful PAR lighting. I keep my schedule at around 10 hours or so. It really is determined by the animals, then by lighting, then schedule in that order, in my personal opinion. Thanks for participating! ~Paul> Heaters I have a question about heating the tank. <sure> My main tank is a 50 gallon and I have a 29-tall underneath serving as a sump.  In the main tank I have a 150 watt Ebo Jager and a 100 watt Ebo Jager heater.  These heaters stay on most all the time.  Sometimes one or the other will go off briefly.  My question is, does it hurt anything for them to run almost continuously?  I have a large ritteri, an ocellaris, and a bicolor blenny.  I keep the tank around 81 F.  The temp is very stable.  The room is usually in the mid-70's.  Is it okay for the heaters to run so much? <Shouldn't be a problem, seeing as that's what they're made to do.  Ebo-Jager heaters are very durable, so I wouldn't worry about it.  Also, for future reference please capitalize "I" as well as the first letter in every sentence.  M. Maddox> The Heat Is ON...All The Way ON! (Heater Too High) Yesterday morning I cleaned my tank, moving tubes around.  The heater I have has the temp dial housed with the plug that plugs into the wall, well moving things around pushed the dial on the heater all the way up! <Yikes!> It sat like that for about 8 hours reaching about 110 degrees, when I got home, I quickly changed some water and had the temp down a few hours after that!  So, lets see, Flame Angle, Bubble tip anemone, cleaner shrimp, feather dusters, Pseudochromis- DEAD.  Mostly all of the turbo snails and hermits died also. <Sorry to hear that!> The Tomato Clown and Purple Tang are still alive! (clown is lonely without the BTA). Bubble Coral and Toadstool fell apart.  I have Mushroom Corals (hairy/Bullseye), Button Polyps, Sally Lightfoot and a large clam (I think still alive).  My questions would be this, is the live rock ok. I mean the bacteria that makes it live, will the tank need to be recycled?   <Good question. Bacteria are among the most hardy organisms on earth, so it is likely that the majority of the population survived. However, do monitor water quality to confirm this. You can always make use of a commercial "bacteria in a bottle" product to help kick-start things if needed.> Will the tang and clown have problems? <Hard to say. If they made it this far, they should be able to survive. Keep an eye on them!> Is all the purple encrusted algae dead? <Again- hard to say...You will just have to maintain proper conditions and hope for the best...> Should I remove anything that would eventually be a problem?  I guess what should I do now, clean it up, let it sit for (how long) then BUY A NEW HEATER, then add new fish.  In other words how bad is the aftermath?  Any comments or suggestions would be appreciated <You're on the right track here...Observation and upgraded husbandry are the vehicles of choice here. It may not be as bad as you think. The worst may be over. Monitor your fishes and water quality carefully here, and stay on top of routine husbandry practices (water changes, protein skimming, etc.). Continuous use of chemical filtration media (activated carbon and/or PolyFilter, etc.) and a lot of patience will see you through! Do get that new heater ASAP. Good luck! Regards, Scott F> Mark Halatin Temperature tolerance, So, I'm looking for the expert the experts look for answers - or something like that :) Let's say this winter your heat goes out and your reef tank or tropical marine fish tank is chilling.  Let's just say you go 24 hours without heat.  At what temperature do you think things would start to die/suffer beyond recovery?  Or rather, what temperature do you think you'd have to keep the tank at, as a minimum, for everything (or at least almost everything) to survive without permanent damage or real troubles (coral bleaching, brain damage, etc.) I have looked, and looked, and looked and can't come up with much.  Upper limits I got, lower limits I don't. I know reefs don't form lower than upper 60s, and Borneman says some tough corals can survive 40s - for a few minutes - but that's about all I can find.  I really can't come up with anything at all for tropical fishes and inverts - other than personal experience.  I KNOW they can go for a day in the upper 60s (been there, done that), but two days or more??? Opinions/answers will be greatly appreciated! Cheers, jf >>>Greetings James, This is an area that us keepers, for obvious reasons, avoid doing much experimentation... Temperature tolerance varies greatly from species to species, and from individual to individual, setup to setup. Another important factor, just as with heat spikes, is how big the spike is. If a reefer was keeping his tank at say 83, like I do, then a drop to 70 is a major cold spike. On the other hand, a spike to 88 means little. (which is why I maintain higher temps) Anyway, Snails and crabs will be the most tolerant, followed by the fish. Fish can be quite forgiving in this department, but nothing is all the time. It's impossible for me to give you an across the board, safe low temp for corals. My advice is, don't test the envelope. Even if I told you my system recovered from a 65 degree stint over 2 days without a hiccup, that doesn't mean it won't wipe your system out. Don't assume that because a wild coral will tolerate a drop to 62, that your captive coral will. Keep your temps from dropping below 71 for any appreciable length of time. If you feel you're in danger from power outages, keep a generator on hand. Cheers Jim<<< External heat from pump Crew: <Hi Rich how are you tonight? MacL here with you> In order to give my wife back the living room, I am relocating my 55 gallon FOWLR in the basement. <Nice of you but I bet she misses the tank when it's gone.> Currently, I have four fish in a Rubbermaid container with some of their LR and a powerhead, the 55 is filled with water, sand and the rest of the LR, and my Iwaki 40RLT is running on a closed loop.  The problem is the heat. The ambient temperature is 74F, and the tank is running around 82F! <I have to say when I got this email I was very surprised. I have not heard of an Iwaki running that hot. I checked with another WetWebMedia person and they said the same thing. They also felt it was pretty much impossible with the set up that you have, to have that large a jump in temperature.> I have not even turned my lights back on yet.  My pump has been is use for about a year. I have it installed on a small homemade stand in back of the tank, about 3 feet high, to lessen the head pressure. <The thought was perhaps you had the pump inside a cabinet or other enclosed place where there wasn't proper ventilation. In that case, it might have caused a larger that usual jump in temperature but as I understand this you have your pump in an outside area. The next thought is that perhaps your you need to check the calibration of your temperature gauges. I can speak personally to this one. I usually run three or four temperature gages at a time on my tanks.> The intake is installed over the top on the right side, using two 90 degree elbows.  The output goes up about one foot, splits with a "T", and runs to both sides of the tank, and up and over with elbows again.  I have read that Iwaki's, and external pumps in general impart less  heat, so I was surprised to find this much of an increase. I do not have any previous temperature readings with only the pump running, so I am not sure if this has always been the case. <I really would check your thermometers, a rise of perhaps three or four degrees is more normal and Iwaki is pretty much known NOT to have that kind of rise.> The pump is not making any loud noises or anything. Any ideas?  I was looking forward to more stable temperatures in the basement. I am trying to hold onto that dream! <Check the calibration of your temp gauges, both inside the tank and outside of it. If when you check it you find it really is that large a jump please let us know again.> If I read wrong, and Iwaki's DO impart heat like this, can you recommend a brand that does not? <I think you have the best Rich, Please let me know how this turns out. Take Care, MacL>  Thanks, Rich

Temperature Fluctuation Hi again. <Hi, MacL here with you tonight> I am a little worried about my water temperature, I really don't know where it should be right know it is at 26 degrees Celsius <26 degrees Celsius, equals 78.8 Fahrenheit which is generally considered the perfect temperature to keep saltwater tanks.> and when I turn on the a/c it changes. <The big question is how much does it change. Large fluctuations 3 to 4 degrees can mean real problems for the tank.> I would like to know what are the degrees of changes I should have so it is ok for the fish. I don't have a chiller, I live in Panama in central America so here it is hot all year round, <Lucky person> the tank is in my room and the a/c is almost off all day and on in the night and when I leave sometimes it stays off for the weekend will these affect my tank? <It really depends on just how hot the tank gets. I would advise you to keep the tank very under populated and keep lots of oxygen in the tank with extra powerheads.> What are the temp. I have to have, I got that Big Digital Temp. alert, I would like your help so my fish wont have a hard time. thank you

Temperature Spike- Loss of Livestock 7/6/04 Hey There- You seem to be the end all resource here so I have a few questions for you.  I got home from work last night to find my reef tank a whopping 83.5 degrees.   <hmmm.. the temp is not so terrible when the climb is/was slow. Many reef creatures can tolerate much higher temps. But in general, more then 2-3 F spike over a short period of time can be rough> I added a frozen bottle of water to the tank to bring the temp down but it appears I have lost some livestock and everything in the tank looks ill.   <a sharp drop can be equally stressful. Do note this for future reference. All good and bad things should happen slowly in aquaria <G>. The first thing to do in such cases is heavily oxygenate the water. Turn up venturis, add an airstone and/or add fans to blow across the tank. Improved O2 and slow temp reduction> My LT Anemone hasn't melted but was found in the back of the tank with a lot of the mucous looking stuff in the trail of its path.  The cleaner shrimp was dead, and my goby, wrasse, and blue tang look like death has touched them.  I did an emergency water change this morning (20%).   <excellent... when in doubt do a water change - agreed> Is there anything else I can do to save my tank???   <a few more large water changes in the next week or two> I took the anemone out and put it into a hospital tank to see if it opens up again.  If not I think it shall be the toilet for him.  My live rock looks ill as well (the mushrooms and zooanthids are closed.)  What happened during the temperature spike-  The tank is normally 78.3??  Did the temperature spike cause an ammonia bloom????   <more likely sudden oxygen deprivation> Will a water change be sufficient to bring this under control or am I S.O.L.??   <no worries... the tank can get right back on track. DO consider adding a fan to the timer for the lights, or run full-time if needed. It also would not be too expensive to add a fan to blow across the top of the tank plugged into a thermostat> Thanks for you time on this matter.  Russell Sacramento, CA <best of luck! Anthony>

- Dealing with Heat - Howz it goin??   <It's goin'...> I have what could be a problem... I am living in Ottawa Canada, and our summers are VERY hot.  It was 34 degrees today, and my fish tank's temperature is currently at least 31.  First of all, will this be a problem. <Yes... it will raise the metabolism of anything you are keeping in the tank - most certainly will be fatal for corals. Fish can tolerate it for a while, but not for too long.> If so is there anything I can do to fix it. <I'd start by running a fan across the surface of the water... then, perhaps lighting the tank opposite daylight, to avoid heat build up... there are other options, but I would start here.> Thanx for the help. Steve <Cheers, J -- >

How much can they take? Temperature question. >Hi, Hope all is going well there for you. I have a couple of questions for you. First of all, I live in south Florida and the temperature of my tank during the summer is usually 80 during the hottest part of the day (even with heaters off). Early in the morning when I wake up to go to work the temp usually drops to 78. Is this too much of a temperature change in about a 12 hour period?  >>It's pushing it, but no, it's not terribly bad. >Should I set my heaters to 80 so that the temp won't drop during the morning hours?  >>How about this? I'll meet you in the middle at 79. >Also, my tank is a 75 gallon F/O with 2 false perculas, 1 flame hawkfish, 1 royal Gramma and 1 coral beauty angel. I am thinking of adding a yellow tang in the next few days. I know he will probably be the most aggressive fish in the tank. Do you think there is anything to worry about as far as fights?  >>No, I honestly don't think so with that mix. If you can make sure it's a smaller juvenile then you should be golden. >Thanks for your help, James >>Quite welcome, James. Marina 

How to handle a heat wave >Hi all, >>Greetings, my apologies for the late reply. Your email has been in another's folder and I just found it. >I have a problem. I keep a 75 gallon saltwater tank with a 6" Volitans lion and a 4" Long Longnose Butterfly. I live in the southern US. Recently, the heat pump outside the house gave out. With temperatures inside the house climbing to over 100 degrees in the hottest part of the day, I am EXTREMELY worried about my fish. I have turned off the aquarium lights and directed a fan over the top of the tank that stays on all the time, but the temperature still climbs to above 86 degrees in the tank. With repair on the heat pump expected to take 2 weeks (!) and no local fish store willing to "board" my fish, what can I do? I work during the day four days a week, so a hands on solution is out. Worried!!! Frank >>You should have in place a system of fans to utilize evaporative cooling, along with an automatic top off for adding freshwater in order to keep the salinity stable. This can be quite simple, using gravity feed and a few 1gallon plastic jugs or soda bottles - you silicone in some airline valves and set the drip rate manually. Or, it can be a dedicated top off system with float switches, etc. Also, you can fill some plastic jugs (must have screw tops or otherwise be SEALABLE), those "Gladware" reusable, sealable plastic containers, or, in a real pinch, Ziploc baggies (I'd go with freezer quality bags, just to be sure), fill with water and freeze over night. Let them float in the tank for the day, but be careful with this method, as you could cause too much of a drop, which is harder on the fish than a rise. Let the temps stay around 80-83F if possible. Marina 

The Dreaded Heater Mishap! >Dear crew, >>Hello. >First, thanks again for all of your hard work and patience. I am writing because I had a heater mishap, I must have turned the dial without noticing and the next morning the tank was up to 96 degrees! >>It is not unknown for thermostats to become stuck in the "on" position as well. Sounds like you've got a bouillabaisse going there, eh? Very sorry to read it. >Well, needless to say some things died (Coral Banded Shrimp, Mushrooms, and I think my purple Pseudochromis). Yellow Tang, damsels, percula, snails, and hermits- all OK. >>Real bad, sorry to read this, mate. Glad you didn't lose the whole lot. >I can't find the pseudo I think he must be dead inside a piece of live rock.  >>Could be, or the hermits got a hold of his warm carcass. >I can't think of a way to get him out if he is dead, because he gets in the smallest of holes.  >>As those Pseudos are often wont to do. >1) Do you have a suggestion of a way to maybe get his little body out? >>No. >2) If not, how long will this affect my cycle? >>This depends on many things, but you can certainly boost it with Bio-Spira. This is the good stuff <opens trench coat> right here. >3) Is the best thing to do is just frequent water changes if I can't get him out? >>Yes, and do them anyway. You may need to do one or two really big w/cs - on the order of 75%-100%. Make sure you've aged that water at least a full day, two or three are better. Match everything, as I'm sure you know. Oh yes! Be SURE to bring your tank temp down slowly! No more than two degrees Fahrenheit/24 hours. >Thank you so very much. Sincerely, Keith Tallbe >>Again, so sorry to hear this. Get that Bio-Spira first thing, then mix up the water anyway (it's always good to have on hand). Best of luck, and if you don't have a hospital set up, be prepared. This sort of thing may spur on some stress-induced troubles. Marina 

Fish Heater 4/27/04 I am currently doing a project involving testing a material found in the knee.  To do this, I must have the material be body temperature (98 F).   I thought of using a fish heater to heat the water that the material will be placed so the material so the material will be at its normal temperature.  I was wondering what fish heater you would recommend using (should be 100-150 watts) and how might I go about tweaking the heater so it can reach that temperature.  Also, if you can give me the names, email, URL, and phone number of their manufacturers, that will be greatly appreciated.  Thanking You, ~Huma <Hi Huma.  Most aquarium heaters aren't designed to heat water to such a high temperature.  If you have to get all the way to 98F, you may have to use some kind of lab heater on a temperature controller.  Ebo-Jager heaters will heat up to 94F.  Won Pro-Heat titanium heaters go up to 93F.  I found these products and their specs by doing browsing www.marinedepot.com.  You could also shop here: http://www.drsfostersmith.com/product/shop.cfm?N=2004&ref=wwm&subref=AA  Dr. Fosters and Smith is a WWM sponsor, and we always appreciate support of our sponsors.  Best Regards, Adam.>

Temperature Issues  Hi-I have two issues with my tank....One is how can I keep temperature control? My tank is 20 gal. and the water heats up really fast in this sunny hot weather. I can't tell if I keep getting new ich blooms w/ this ever changing water climate (my tank has been running fallow for a few weeks now). I am just worried that w/ the new fish I will put in the tank soon and w/ this hot weather, that I am gonna keep getting ich outbreaks.<I would take off the top and point a fan or two at the surface, if needed cover the top with screen to prevent fish from goin carpet surfing. Also I would let the tank go follow for at least another month to be safe.> The other thing is, I have a turbo snail, and I noticed the other day a baby snail. I thought that turbo snails did not self re-produce, is this true? I don't want my tank to be over run w/ snails-one is enough for my small tank. What should I do about my snail problem?<The snail probably came from some live rock or the like.> Thanx for your help, I love this website!!!! Heather.

- Summer is On The Way - Hello, My reef tank temperature is running hot I think.  It averages about 82 to 84. <That is a bit warm... much warmer and you will begin to lose some of your corals.> All the life in the tank is doing well but it is just the beginning of summer and am concerned. <You should be.> I happen to live in Phoenix AZ so heat is always a problem.  I am wondering what if anything i should do all the lighting is elevated about 2 inches above the glass top. <Start by blowing a fan across the surface of the water... this should lower the tank temperature a bit... if not sufficient you might want to explore having the tank lights on in the middle of the night or perhaps a chiller.> so i know that that is not a problem but still.   Thanks for your advice <Cheers, J -- >

- Heater Scale Deposits - Dear Crew: Thanks for the great site. I am new to marine aquaria. I have two large tanks, 75G and 125G, which I maintain similarly and are 9 months and 6 months old, respectively. Both have 300W submersible heaters. I found a heavy scale on the heater of my 125 a few days ago.  How long it has been there I am not sure but there is no similar scale on the heater in the 75G. Here is a picture of the scale in the 125G: It is orange-brown and has spalled in places taking away with it the decorative glass-stenciling. I am interested in what caused the scale to form because I am trying to track down the cause of a prolonged micro-algae or phytoplankton outbreak in this tank. <They are not related.> The calcium levels in the two tanks are similar (around 500 ppm) but the temperatures are different: about 75?F in the 75G and 83?F in the 125G. Possibly the higher temperatures or longer "on" times could have promoted scale formation in the 125G, but I was also considering another possibility. I thought that the scale formation might be due to my having left a floating glass-cleaning magnet in the tank for two-weeks. <Nah... doubt that. The scale is simply just the product of a high calcium level and the temperatures of the heater right at the surface of the glass.> I had seen other people leave them in their tanks but I took the magnet out after the algae or phytoplankton outbreak because I thought iron might be leaching from it. <Not all magnets are made of steel...> I had difficulty controlling the outbreak but eventually managed through water changes, improved skimming and use of a canister filter. Do you think that increased iron levels could lead to a runaway algae outbreak and produce the scale on the heater? <No... that is just calcium and very normal for just about any accessory attached to a marine tank and not regularly cleaned.> Respectfully, Karl <Cheers, J -- >

Ick, heat and lights Hey, <Hi> How long would you let a tank go fallow that had an ick breakout? Is three weeks enough? <I would aim for 4-5 weeks, just to be on the safe side (however, the normal ich cycle will last around 3 weeks depending upon the temperature of the aquarium.)> I am having trouble with rising temperature. Early in the   morning my tank is around 74 degrees. The lights go on for 8 hours. At the end of the eight hours the tank is 78 degrees and that seems like a big temperature change to me. Are PC's considered heat hogs? <They can be if you do not have proper ventilation> I have a 96Watt Coralife PC on a 40 gallon reef tank. I have a glass top but I keep the lid cracked and I have a hang on the back filter so the tank should get enough air, but maybe not. What do you think? <Because the temperature seems to raise while your lights are on, I'm thinking this heat problem is due to the lighting rather than pumps creating extra heat. Adding fans to your canopy should help out a lot. If you have a glass lid over your aquarium, you may want to consider removing that because it's most likely trapping heat in your aquarium. May I ask what the room temperature is during the day?> My friend wants to do a 20 gallon long mini-reef tank, but he just wants mushroom corals. I have been successful propagating mine and will "sell" him a few rocks, lol. What lighting do you recommend if he is just doing mushrooms, i.e. reds and blues? <Whichever Kelvin temperature your friend likes best. Mushrooms will do quite well under a wide variety of spectrums.> Can he get away with a 30" fluorescent or does he need to get a 24 inch, 65 watt, PC? The PC is more than twice as much! It is also $19.00's more than a double bulb florescent. Which of the three would you recommend? <For best coloration and growth of the mushrooms, I would highly recommend the 65wt power compact.> Thanks. <Take Care, Graham.> Nathan West

Lighting Cycle for Algae and Heat Issues? >Hello, >>Hello. >I started my refugium with Caulerpa around 2 months ago and during that time I had my two 65-watt power compacts on 24/7. >>No need to light 24/7, my friend. >About 3 weeks ago I removed the Caulerpa and replaced it with a good sized piece of Chaeto using the same amount of lighting. >>Amount AND duration?  Again, no need. >During this time the Chaeto is growing like crazy which is a good thing and my nitrates have been a constant 0. >>Low nitrate readings are indeed a good thing. >The bad thing is my water temperature is varying a couple of degrees throughout the day due to the heating from the power compacts. >>Not really, a couple of degrees is certainly tolerable.  I will ask you one thing, and it's the most important thing: do any inhabitants in the display show ANY negative reaction(s) to the slight change in temperature?  Many folks get so caught up in monitoring parameters that they forget to simply use their own powers of observation, which are often much better than they realize.   >My question is do I still need to have the lights on 24/7 for the Chaeto? >>Not for either. >If not what would be a good cycle to use? I have heard that a good scenario is to have the refugium lights on opposite of the main tanks. >>Only if you're having big pH shift issues is that necessary.  With my own first system I devoted a full 1/3 of it to Caulerpa, which meant that it was lit when the corals were lit.  I had NO problems whatsoever. >If this is the case should I gradually switch to that timeframe or will an immediate effect not cause a problem. >>I don't think you'll cause the algae any great stress should you decide to go this alternating cycle, it's not got a nervous system with which to react to such changes.  Plus, if you think about it, many of the animals we buy come quite literally from the other side of the world.  The time zone is quite different, and after a period of adjustment, they can fare quite well.  This would be even more true of algae. >My concerns are if I turn the lighting time down I will get nuisance algae growth in the refugium. >>With no excess nutrients you shouldn't.  Nitrate would not be the only issue, of course, but this is part and parcel of WHY you are growing the macros, isn't it?  ;) >Thanks, Tom >>You're welcome.  Marina

Trying to Find a Balance >I have a 40 gallon breeder tank with JBJ 192W compact fluorescent lights, glass covered top, and a JBJ 1/10 chiller. The tank fluctuates between 76.5 at night (no lights) and up as high as 79 in the winter and in mid 80's in the summer. I have the setting at 77.7 right now which chills 1 degree below that (76.7) and kicks on 1 degree above that (78.7) should I allow it go get warmer before the chiller kicks on say 79.7? My house is a ranch with a bonus room above the garage. Its warm year round up here! I want the tank to be the right setting while also being as efficient as possible. I am afraid with the setting too close together it will stress the fish. What do you recommend? Thanks, Rob >>I recommend that you keep the temperature within as tight a range as possible. Large (defined as being +/- 5F) temperature swings are MUCH more stressful to fish than most folks realize (especially downward). I'd set things up to keep the tank between 77-80F. Marina

Titanium & Electricity (12/17/2003) Hello Good friends! <Hello to you" Can you all tell me if one needs to use a grounding probe.. (titanium) if one already uses a titanium heater? Does the titanium heater double as a grounding probe? Boy could I use just one more outlet! <It will not work as a ground because the titanium case does not have any direct connection to ground and the heater is plugged into a live wire. If you need the outlet, get a 3-prong multi-outlet extension cord or power bar. It's the third prong that is the ground on a probe; the other two are non-conductive (plastic)> Also, my titanium heater seems to have my fine aragonite sand baked onto it??? <I have a hard time seeing how this would be a problem or danger, but you might try wiping in off. You could also contact the manufacturer and ask them what to do.> Any help would be appreciated? <hope this helps, Steve Allen>

Heater problems I recently received a response about some heater issues that I have been having. Here is the scoop, I have a digital thermometer that I've calibrated at my LFS. My temp in the tank has episode were it fluctuates throughout the day. Usually it stays around 78 during the day and drops down to about 76 at night, but on more than one occasion I've woken up to find either my temp lower or higher than my heater is set at. In my latest incident I woke up this morning to find my temp at 81.5 and my heater is on! <yikes> Its only set at 78 and it is practically a brand new Rena cal. What is the deal? Should I move it out of my sump? <if the temp is the same in the tank and in the sump, No> Is my heater malfunctioning? <sounds like it>     What do you know about the titanium heaters with the digital controls? <love them, use them all the time MikeH>

One Hot Clown Trigger! Hey, I have got a clown trigger (3in) in a 55 gal. <Larger quarters in the future? Please say yes...> Yesterday my heater spazzed out on me and the water got really hot, probably 90-95...really hot to the touch. <Yikes!> My Koran angel, yellow tang, and 4 stripe damsel all looked fine still, but the clown trigger was breathing very rapidly and having trouble swimming.  Once I noticed the problem, I took out 5 gallons of the tank water and switched it with 5 gallons of cold water and removed the heater, this cooled the water down a lot, for the past 14 hours he has been under a piece of my live rock, still breathing heavily and not moving around, his coloration is almost entirely black-the yellow is very dark, and the white spots are dark as well.  My biggest worry now, is I noticed that his eyes seem cloudy, and maybe bulging( I can't really tell because of his location) He is not eating, or swimming at all, but the other fish still eating and behaving normally. So, my question is, should I remove the trigger and treat him in a doctor tank, if yes then with what? And is there anything else I can do?  Thanks a lot Eric <Well, Eric- first of all, please perform any and all treatment in a separate aquarium. It is hard to say exactly what this guy may be suffering from. Some of the symptoms that you are describing are similar to those which accompany bacterial infections. However, many times, these maladies can be corrected with very simple means, such as maintaining very high quality water conditions (use aggressive water changes, protein skimming, chemical filtration media), and overall stability. Removing the fish to clean stable quarantine conditions could make a big difference. I'd try this and see if any improvement occurs. Otherwise, you may need to utilize an over-the-counter antibiotic (once again- this assumes a bacterial problem) once you confirm what you're dealing with. Finally, I do once again want to urge you to provide a larger aquarium for your specimens. Both the Clown Trigger and the Koran need a lot of water volume and sheer physical space, both to ensure long-term health, and to dilute their substantial metabolic wastes. Keep a close eye on things, and tweak as necessary. Good luck! Regards, Scott F>

Busted Heater, toxic bucket? Hi Bob, <Hello Joyce> Joyce Mahoney here. Long time no see. Are you going to the MASLAC X-mas party at the Queen Mary?? <Not planning on so at this point, but maybe> I am going to try to attend as I have not seen anyone for some time. I had to stop going to the Friday night meetings as they are too far from my home and the Friday night traffic going into Los Angeles is brutal.  It seems that on Friday night the last thing I want to do is hit the freeways about 5 pm to go to the meetings!!! I hear that next year they will change the day to Saturday. Should be better. <The traffic IS a MAJOR determinant in my going anywhere as well> I have a quick question for you. Yesterday my glass heater broke in my water makeup barrel. I am wondering if the blue plastic barrel and the mixing pump are ok to use? <Should be fine. Just give them a freshwater rinse>   I do not think the heater was on at the time it broke. I went to use my water and found the broken heater, but the circuit was not tripped, so I think it just got knocked by the pump and broke. I emptied out the water and glass from the barrel and rinsed the barrel and pump with clean water. <Sounds good> I am thinking it is OK to reuse the barrel and pump, but I thought I'd ask your advice. Hope to see you soon, Joyce <Be seeing you. Bob Fenner>

DOH! I Broke the Thermometer, Now What?  >Hi Bob and team.  >>Hello, Marina tonight.  >I'm afraid I've had a disaster in my 200 gallon reef aquarium. While recently double checking my chiller reading, I stupidly left a thermometer in my sump. I found it this morning, broken at the pump intake.  >>Oh my, thusly the term "disaster". It's not as disastrous as you think, though.  >The lead balls have been sucked into the pump and the mercury is gone.  >>Not mercury anymore, my friend, usually alcohol (with a dye) is used in modern thermometers.  >Everything in the tank looks OK so far (corals and fish), but I can't imagine that'll last. What should I do? I'm sure water changes, carbon and PolyFilters will help but I can't imagine I'm ever going to find the lead balls?  >>No, I don't imagine you will, either. But I wouldn't expect such a small amount to be a very big problem in the short or long run anyway. If you're very concerned about the contents, contact the manufacturer, but to the best of my knowledge the potential for mercury would be the biggest issue and as far as I know it hasn't been used for quite a few years. You're correct, water changes, carbon, and PolyFilters will help, though I don't know at all how readily lead actually dissolves in water (thinking of wrecks of Spanish galleons and all the lead shot/balls they find, all encrusted with stuff).  >Any advice you can give would be great. I hate the thought of tearing down my tank and starting again. Dave.  >>No, no, no, I really don't think you'll need to go so far. Between the water changes and the chemical filtration you should be able to deal with the small amount of dye released. For "next time", get a bit of clear plastic tubing, the kind used for undergravel filter lift tubes, along with caps. The caps can be the same clear plastic, or PVC that fits. Glue one end (I'd use Superglue-cyanoacrylate) on permanently, leave the other so you can slip it on and off. Drill some holes in the tube, and it will protect the future thermometer from such terrible mishaps. Marina 

- Heater Won't - My Jalli 500 watt heater keeps quitting on me. <That's not good.> I have a 90 gal tank with a 20 gal sump, the heater is in the sump, has never come out of the water while plugged in, is not covered by anything, the control head is properly mounted and connected, temp probe is in the middle of the tank.  I just got the entire heater replaced 4 weeks ago, under warranty, because of the same thing. <Nice to see they're batting 1000.> Is this a cheap heater? <I'm not a huge fan of Jalli, but I know someone who is and swears they [Jalli] try very hard to get past problems like this. If it were me, and I'd had two heaters broken, I'd ask them to buy me a new heater. There seems to be a flood of heaters with electronic controls coming from Asia... I think each one needs to be well tested before tried on your main tank as you might be in for a surprise.> Would I be better off with 2 -250 or 350 watt units? <In the cold parts of the country, I would suggest having two 350's with one set a little lower as a back-up should the main one fail. With larger heaters, they tend to be 'on' less often, can heat a given volume of water quicker and I think [in my own weak non-scientific study] they will last longer. Any under or exactly-sized heater that is 'on' all the time will break eventually, regardless of brand - is just my observation, but have seen it happen often enough.>  I do have a 250 watt backup working now, it struggles to keep 78 degrees. <Using two 250's would guarantee the failure of one, and then the other.> Chilling here in Pa, thanks... Mike <I believe it. Cheers, J -- >

Keeping Stable Temperatures, Or "Just Chillin'"  >Good Morning Crew;  >>Good evening folks.  >Now that the weather is changing and the outdoor temps as well, what is the best way to stabilize the temps in our aquarium (75 gal)? During the summer months and having the house a/c on the temps were good and into the early fall. We have had this sudden spurt of warm weather but not requiring a/c, the temp in the system is running 79.3 - 80.5 digital. If I keep the doors on the base open it will come down to maybe 77 or 78.  >>Not knowing what you're keeping, it seems to me that as long as whatever it is is tropical, you're WELL within acceptable limits.  >Have checked the heaters and they are functioning fine, set at 70 one at 72 (one in tank, one in sump). Do you need to have a small chiller to run with the heaters in the winter when the household heat comes on?  >>Folks use chillers in conjunction with heaters to keep tank temperatures within very tight parameters, this is considered a year-round issue. If this is what you wish to do, then a chiller would be the best route.  >I usually like to run my tank around 76-78F maximum. This is our first fall into winter for our system, having set it up in February of this year. Thanks once again, have a great weekend.  Ceil Wagaman  >>Thank you, yourself as well, and you're welcome. Honestly, though, I would think that hitting a high of 80F isn't much of an issue, but if you feel more comfortable keeping tighter parameters, as I said, then a chiller would be the most precise method. Marina 

Tank Temperature 10/8/03 I have had all kinds of advice on tank temp. Anywhere from 72 f to 78 f. What temp do you prefer? And what temp would you recommend for a 40 gallon reef tank with 3 fish and lots of coral? My current temp is steady @ 75 f. Thanks, Jason <the water temp depends on what you will be keeping. Freshwater or Saltwater, and fishes from what region? In general though... 76-78 F is a good range for most tropical species. Anthony>

- Specific Gravity & Temperature - Hi, Hope all is doing well there.  I have a 75 gallon F/O tank.  My fish are:  2 percula clowns, 2 lemon butterflies and 1 coral beauty angel. Please tell me what you recommend for tank temperature and specific gravity.  I have been keeping the tank at 76 degrees and the specific gravity at 1.021.  Thank you, James <James, I'd shoot for 1.025 for salinity - it's what the ocean is typically at. As for temperature, you could go a little higher, but there's nothing wrong with 76F - 76-78F is ideal. Cheers, J -- >

- Temperature Variation - Hi Greeting from Singapore ! I recently started a Tropical Marine Fish Tank, this is what I currently have: 2ft tank - I assume at least 50litres of saltwater. I am using Chemipure and ceramic rings as my main medium for filtering and I have the following. 4 damsel 1 clown fish 1 cleaner shrimp 1 boxer shrimp 1 slug 2 camel shrimp What I would like to check is whether my tank temperature which varies between 28 to 30 degree Celsius alright for my fishes? <Not really, in the short term it's probably ok but in the long term, you probably don't want a variation of more than one degree Celsius in any given day.> Can I put in anemone with such temperature or should I use a ventilation fan to bring down the temperature to 27 degree Celsius? <I'd work on bringing the temperature down for everything in your tank, but the more important factor for anemones is lighting... you need really intense lighting to keep an anemone.> Your guidance and advise is very much appreciated and please reply me via email as well. Thank you Terence <Cheers, J -- >

- Temperature Variation, Follow-up - Hi Thanks for your prompt reply <My pleasure.> So, is it ok even if I leave the temperature alone which usually stay between 28 to 29 degree and only during certain month it hit 30 degree Celsius? <Yeah, I think that's ok.> When you said short term...what does it mean ? one month ? <Something like that - it's just that 30C is really higher than is healthy for your animals. Sustaining them at this temperature for more than a couple of weeks will increase their metabolism and foreshorten their life span - also lessens the amount of dissolved oxygen, so all in all... the ideal temperature range is 24.5 - 25.5 Celsius.> Cheers Terence <Cheers, J -- >

- Temperature Variation, Follow-up - Hi Thanks again... but even with the fan on, the temperature I hit the lowest is 27 degree Celsius. Is that ok or would it better to let the weather determine the temperature? <In your case, I think trying to keep the temperature as close to 25.5C is best... so if it's 27C, then so be it. It's not ideal however, but much better than leaving things up to the weather.> My tropical tank is always around 28 to 30 degree and I see that they are still swimming happily. <You may have noticed that they are breathing rather fast - because fish are cold-blooded animals, their metabolism is regulated by the temperature of the water around them. They can survive at higher temperatures, but their metabolism runs faster... and will eventually shorten their lifespan.> Would it be better if I turn on the fan only when it hit 30 Celsius to bring it down? <No, much better to keep things as steady as possible, as well as on the cooler side.> One more question, must I get a anemone for my clown fishes and what is it purpose? <No - in the wild, they protect each other, have a symbiotic relationship. In captivity, clown fish can do quite well without one. Anemones are not easy to keep, and require high intensity lighting to thrive. This same lighting will create more heat in your tank, and I can assure you at the temperatures your tank is running currently, an anemone would not last for very long there.> Apologies for all the questions, just that I am a newbie where marine fish is concerned. <Consider reading some of the articles that make up Wet Web Media, we answer questions like this all the time and archive them for your perusal. Here's a good place to start: http://www.wetwebmedia.com/marine/inverts/cnidaria/anthozoa/anemones.htm http://www.wetwebmedia.com/temp_faqs.htm > Thanks <Cheers, J -- >

Tank overheated, everything dying! >Hello All, >>Greetings, Andrea, Marina here. >I live in Northern California and we had a heat wave that lasted about 4 days last week.   >>Indeed, I have a sister in Pleasanton, it can be most Unpleasant. >I have a 100 gal tank that got up to the high 90's a few days ago, stayed there for about 2 1/2 - 3 days despite everything I could do (while freaking out) and then dropped back down to its normal temp of around 80 degrees.   >>Even setting up fans to blow across the water's surface?  That can usually keep it relatively under control, unless you're in a terribly humid place. >Enough water evaporated to bring the salinity off the charts, even with constant water changes with ro/di fresh water.   >>I am unclear here, did you top off with the RO/DI, or did you perform water changes with fresh saltwater *made up* with RO/DI?  If you did the former, the salinity should NOT have swung like that.  If you did the latter, you have learned from your mistake (and so will many others). >I flushed my colt yesterday after moving it to a 5 gal nursery tank (it was sloughing off large amounts of purple ooze before it died) and I flushed my scissor tail.  I can't find any of the other fish except the clown because he won't leave his anemone (which doesn't look that good either).  Is there any chance any of the following fish will re-surface alive: coral beauty angel, mandarin goby, scooter blenny, red and purple fire gobies?   >>I would begin moving things about, as well as performing tests to deterring how much of an ammonia/nitrite spike you have.  This can tell you quite a bit as to how much die-off you've experienced.  FYI--many of the invertebrates you've listed *should* have been able to survive the temp spike, but few will survive large swings in specific gravity. >Also, can a devil's hand survive that kind of water and salinity fluctuation?  How about a sea whip (gorgonian) or a Montipora capricornis that is starting to bleach?   >>Truthfully, your own observations would answer this better than I.  I could say, "No, they won't", but I've known many who have suffered similar and survived.  I could say, "Yes", but have known many that didn't survive.  WATCH.   >Some of my mushrooms seemed to have partially melted.  Is there any chance they will come back?   >>Not the "melted" ones. >How about the star polyps that have retracted? >>The stars would be most likely to survive, but you really do need to ensure you've got proper salinity, not just temp, and do HUGE, frequent water changes this week.   >I appreciate any advice you can give.  I am off to tear apart the tank now to try and find the lost fish and discard anything dead.  Maybe I should take the tank down and just stick to diving, I am so heartbroken.   >>Well, we don't want that, and, if I recollect correctly, a dive computer's cost just about equals that of a good chiller.  I do hope this helps, try to get everything that's dead OUT--ASAP.  Remove the rock, frags, gently flush with saltwater to remove dead, dying, and debris before replacing into the tank.  Large trays (like cat litter trays) are helpful to have around during this process, just for holding while you're cleaning up.  Also, do join your local club, you wouldn't BELIEVE how many people will step up to the plate to help out with cleaning out, restocking, donating frags and the like.  Same thing goes with many of the internet boards, such as our own at http://www.wetwebfotos.com/talk .  Best of luck to you, Andrea!  Marina

Thermostats for Fans, Chillers, Heaters Hello guys, Can anyone tell me where I can find an adjustable thermostat with a submersible temp probe that I can Connect my cooling fans to. THX, Wayne. <Sure Wayne! Surf over to one of our fine sponsors and look at the single and dual stage therms for heaters and chillers. The single stage will run either a heater or chiller and the dual stage runs both a heater and a chiller. Either will work for your application, just plug in the fan instead of the chiller. They are a bit spendy, but worth it!  Make sure you tell them we sent you! Have FUN! Craig>Question on my reef tank Hello i have a Visi Therm fully submers 300 watt heater is this sufficient enough for my 75 gallon tank? i set it to 82 and it has gone up one degree in the past 3 hours is that right this is brand new so i guess it worked right its gone from 80 to 81 in 3 hours?<This will be fine 82 is a little high though, I would do more around 78.  Cody> thanks JM

Ice Probe <Good evening, PF here with you tonight> Hello Crew, hope you all are doing well. I have a question about those little Ice Probe thermoelectric chillers, the one you can stick through a bulkhead and bring down a 55gallon tank 12 degrees, according to the ad.  I have a 90 gallon that I would like to drop a few degrees, would it be possible to use two of these to do this?  I already have two muffin fans in the canopy for cooling the halides, they are really no problem.  But my Velocity T4 pump and the in sump Rio2100 for the skimmer are major heat producers.  I don't want to run extra fans over the sump for more cooling by evaporation (I don't have an auto top off ) it might have a negative effect on my salinity. Right now the tank is running without lights ( it was just set up ), and it is hovering around 82 - 84 degrees!  The house is only around 76 degrees, cooled by central AC.  What is your opinion? <Well, you can also place them in small HOT (hang on tank) filters, I've seen that done (and offered on EBay that way). You could also bite the bullet and buy a chiller, it would insure better temperature regulation. You can find them for decent prices, it does take some searching though. I would also recommend reading this: http://www.wetwebmedia.com/temp_faqs.htm > Thank you. <Your welcome, have a good night, PF> Overheated tank >Folks, >Thanks for your advice to be patient following the stuck-on heater episode.  As you said some marine organisms are hardier than we think. All the fish survived the temperature rise to over 95 degrees F (I don't know how long it had been at that). In fact I was adding a little brine shrimp when I realized all wasn't well and the yellow tang (added only two days earlier) fed as if nothing was wrong. The blood shrimp, assumed to be dead, emerged from the rock two days ago and seems fine. One finger coral remains bleached and closed, but then it never opened anyway. The cup coral looks a little worse for wear, but is gradually opening. Strangely the other finger coral, about which I wrote to you the day before the heater stuck because it never opened, has been 'fully polyped' since the time the water cooled down, nearly a week now. The star polyp colony has slowly opened, but the polyps are much smaller than before, and a brighter green. Previously they were a creamy brown, and only showed green under actinic blue light. Any ideas? >>Has to have something to do with the zooxanthellae, I would assume. >So the only definite losses to date are two cleaner shrimps. >>Not too bad for almost poaching everything, eh? >Thanks again for your help Brian >>Well, it wasn't me who helped you, but whoever did will be quite happy to know of your success.  Marina

Stability Is The Key... Hey guys, I had two quick questions.  First, what temperature should I keep my tank, which houses a Humu and a damsel. <I like a temperature of 76- 80 degrees Fahrenheit...Stable temperature is more important than any one specific number, IMO> My other question is that I have some sort of reddish dots/algae on the glass that I am not able to scrape off successfully, do you have any clue to what it is?  I do 25% water changes weekly.  Thanks a lot, Jon <Well, Jon- it sounds like some sort of algae or diatom...Hard to be specific without seeing it. However, it's a safe bet that, if you continue to exercise good husbandry (such as the water changes, with high quality water), and utilize various nutrient export processes, than this possible nuisance algae will go away. Good luck! Regards, Scott F>

Tank Temperature Wanted to ask your opinion. . . I have a 200 gal.. FOWLR tank with one Naso Tang, two smaller yellow tangs, one maroon clown, and one Australian Lime Green Wrasse. <Very well, Paul here to do my best> The temperature is a steady 80 - 81.5 degrees (I live in Florida).  The fish seem to be doing great (and have been for two years at this temp) but recently someone told me that the temperature was too high.  What is your opinion? <Well, I subscribe to the technical aspect. Look at the published reports and data that is available related to the area where your animals typically inhabit. Then do your best to meet in the middle ground of the average temps. My understanding is that based on the area of where your fish are collected I think I would subscribe to the average temp of 78-80f without worries. You choose which range of the one mentioned you want to employ.> I am planning to add two Hagen 802 powerheads inside the tank for better current. . . will this increase my temperature significantly? <Maybe a degree or two. Keep an eye on it> If so, any suggestions on lower the temp without having to purchase an expensive chiller? <I don't think you need a chiller. Lower the temp to around 78 degrees and add your power heads. Keep an eye on the temp for a few weeks.> I just can't afford it right now. <No need for a chiller for your set up, unless your temp changes with atmospheric changes during the heat of the day. Being that you are in Florida I wouldn't be surprised to hear that you use an air conditioner to regulate your house during the day. Keep the house around 78f but in any case I would put the chiller out of mind. Ron Toonen has done a great deal of research on tank temperature and salinity in reference to the actual reef environment from where our inhabitants come from. Do a search for him on in your favorite search engine. The great heat and salinity debate is on!!!!> Thanks for your help, <Thank you for coming to our site and contributing. Paul> Elizabeth

Coral reef tank temp.s In reply to a woman living in South Florida, where temps get to the 90's during summer, you wrote: >>>For "disastrously warm" days (where the water is getting over 85F.) floating a previously frozen milk jug of ice can save a system... for emergencies only... And otherwise, just allowing the system to get warmer (low to mid eighties F.) is generally not a big problem (a little more maintenance) for true tropical set-ups (same old reference to coldwater organisms that are sometimes sold as warm in the trade... avoid these...) Bob Fenner<<<< I have a 55 gallon semi reef tank (will be adding Acroporas shortly and had a few questions)...15-20 gal sump and 10 gal refugium I live in HOT HOT HOT South Florida.  Temperature inside gets to a swelling high 80's to 90 degrees without a/c.  Roommate wont tolerate a/c on over 83 degrees. My tank cooks at 86-87 when the house is 83 <Maybe this time of year you can/should switch your lighting period to more in the cooler evenings... doesn't matter to your photosynthetic life if the period is adjusted over time> Chiller is connected and I'm looking for a stable temp of 82 rather then fight over the issue and drop the temp in the house down to 75 so the tank could be 78. Is 82 degrees +/- 1 degree (stable) ok for a reef? <For the vast majority of the species kept by aquarists, yes> Am running two 96 watt PC's (mostly dull, barely fluorescing semi actinic bulbs, and one 250 watt 6500k Iwasaki); 3" cooling fan connected to canopy, blowing directly across the halide (super flow rate of over 500cfm easy); sump is open with plenty of circulation, refugium unfortunately is in a separate cabinet 2 feet away from tank (higher than sump so water is gravity fed back to sump). with refugium lights on 24/7 ecosystem method-miracle mud/Caulerpa, etc.. so some heat generated there with the 20 watt bulb, but cant be much. <Not much> Chiller is a Teclima RA200.  Water from sump to chiller at a flow rate of 150gph (i feel slower is better?. contact time with coils should be longer no?) <Actually... the flow rate being higher will result in the most cooling> The folks at Teclima (in Italy) say min flow rate should be 105 gph yet the folks where i got the chiller say 400 gph is about right.  LOL   Imagine trying to cool water that's whipping by coils at 400gph? <Think about this... the "draw down" (removal of thermal energy is a function of the overall mass, input and contact time... on the extreme opposite viewpoint (no flow) how much warmer would the system water be?> I told the people there that I have a 55 gallon, with 20 gal sump and 10 gal refugium. MH and PC lights, and tank is about 87 degrees when no a/c is on in the house.  Asked them what flow rate would be most energy efficient to run thru chiller.  They were clueless, but I'm thinking. slower is more efficient than faster, no?  Contact time with coils = cooler water exiting chiller. <And warmer/est water elsewhere... You can likely "do an experiment" here that will satisfy your curiosity. Try running the flow rate at both the 100 and 400 gph levels... on different days, graph the temperature results...> You stated "low to mid 80's" to the Florida woman, regarding her reef. <Yes> I'm trying to set my tank up with Acropora/Montipora, and am wondering if 82 degree temp via chiller is ok. I really cant lower the temp anymore than that, or I'd have a blow out fight with my roommate who is the cheapest SOB on the planet when it comes to electric bill. <You can/could calculate or directly measure how much power the chiller (whole tank) is using and offer to pay for it yourself> He states , "that's YOUR tank, not mine". yet he shows it off to all his girlfriend's when they come over and introduces it as "our tank". <Human nature.> Time to bury him under the Deep Sand Bed, methinks. <Make your peace with this trait, try to change it, or seek a new living arrangement> Regards, Steve <Be chatting, Bob Fenner>

Reef temperatures Dear WWM Consortium: <Craig here today...> 55 gallon all glass tank, with 20 gal sump and 10 gallon refugium; currently FOWLR setup and adding some polyps and mushrooms; and now Acropora/Montipora SPS corals higher up near the halide. I have two 96watt PC's and one 250watt 6500k Iwasaki MH bulb (no, I'm not making lava. have fans and a Teclima RA200 chiller). <Hmmm, not out of line to me! I'm running 2 - 175 watt 10K's with two 110 watt VHO actinics on a 55 and it could be 2 - 250's depending on how deep I wanted to keep clams/SPS and placement above tank/light needs of those closer to surface.> My query is the following: My roommate is a cheap SOB and wont chip in to run the air conditioning in the house.  I live in South Florida and inside it can get up to 90+ degrees when the windows are closed and no one's home for a day or so. <Phew....I'm sweating just thinking about it....I'll be right back, I'm gonna go shower....> My chiller claims it can drop a 55 gallon tank down 20 degrees.  I figure my total system water volume is around 75 gallons or so, due to rock displacing some of the water.  Thing is, I'm going to beg my roommate to set the a/c on like 83 degrees in the house this summer.   <Does he run it at all?  You know, I would figure the cost of powering the darned thing and pay the extra myself to not die in a pool of my own....anyway, I would do the math on how many KWH the thing uses (it can't be that much) and try that.  Once he's cool he won't be such a em...hot head.> In your opinion, is it more important to keep the reef from fluctuating 2-5 degrees+/- daily, or to have a constant temp of say 82 degrees? <Same thing, no? Steady at a set point is the same as not fluctuating. It is going to fluctuate some, depending on size and efficiency of heaters or chillers. If you can get it to stay around 80-82F you have no worries my friend!> Believe me I'd love to have the tank at the textbook 78 degree mark, but that'd mean reducing the air temp in the house to around 80...and heaven forbid I did that. <Depends on the textbook. I don't need a chiller, fans are fine in my area, but my heaters are set at 80, and actual is 78.7-80F winter and 78.7 - 83F with a spike or two to 84-85 on the hottest days of mid-summer with no noticeable ill effects. The average temp in the tropical oceans of the world is around 84. If you can get 82, I would relax.> So I'm looking to strike a happy medium here, where the house a/c is basically on "life support", allowing us to breathe somewhat cool air (yes 82-83 degrees is DEFINITELY cooler than the brutal summer 90's we get inside this place). Would it be ok for my corals to live in a CONSTANT temp of 82 degrees? <I don't see a problem, provided all other params are within the norm (water quality, changes, skimming, etc.) It *will* fluctuate a bit from there just from calibration and capacity of the chiller and thermostat, but I wouldn't worry about 82. I'll bet you will actually be able to keep it lower with an 83F house, and maybe down to 79 or so at night. Some fluctuation is going to happen.> I've visited so many reef sites and read that folks keep their tanks in the 80-82 degree range with little/no problems with their corals dying off due to high temps. <You mean temps higher than 82? Doubtful 82F was the causative factor, otherwise many of the worlds reefs should be dead! Hmmm, and all of my corals too!  Not to worry my friend, 80-82 is perfectly acceptable. Do endeavor to keep it from spiking much higher though...> What are your thoughts? (besides killing my roommate and burying him under my DSB)  regards, Steve <That would foul your DSB Dude. No, best to turn on the air, buy plenty of your favorite cool, refreshing, beverages, put the ice chest near the tank (you want it on ice) pull up a couple chairs, and enjoy with your friend. How can he not come around then?  Have fun!  Craig>  

Temperature Fluctuations Greetings all, firstly let me express my true thanks for all of the information you guys have generated concerning this hobby, you have indeed had a dramatic impact on loss reduction, help save the aquarium cash flow by avoiding foolish and unnecessary equipment, between Bob's book, your site, and your willingness to answer questions, I have just turned the three year mark on my 160 which contains of all things a tusk and a blue face (wow, these guys have grown). <So glad to hear that we've been able to help! Believe me, the pleasure is ours! Scott F. with you today!> I am slowly nursing back to health my show queen (Bob's book nailed it, it is incredible how intelligent, curious, and not to mention gorgeous these fish are), I have over time changed over 1/2 the water in the tank, used pH buffer to obtain optimum levels and used Maracyn 2 to cure what appears to be a nasty internal infection. She still is not eating, but finally seems to be coming out more often, hopefully she will be eating again in a day or two (has not eaten in a week, ouch!). <Once she starts feeding, I'll bet you'll see a dramatic improvement in her condition!> Now down to the question of the evening, I read the archives relating to temps in reefs but did not see a guideline as to how much fluctuation per day is too much. I have two 175 halides (and thank you for guiding me toward halides!) on a 55 (I wanted to maximize the amount of tank space that I could grow SPS), the temp even with the fans shifts from 80 to 82 per day. I did see on your page that one degree is acceptable, but wondered if 2 degrees is ok, everything is doing great! (well with the exception of the below stated). <I feel that a two degree fluctuation is reasonably acceptable in a coral grow-out tank. If you are keeping extremely delicate fishes, such as some tangs, which demand high degrees of stability, this would be about the limit. But think about it- in many lagoons where some of these corals may be found, tidal changes can result in dramatic temperature shifts over the span of a few hours. As long as the "highs and lows" fall within acceptable ranges, I wouldn't be overly concerned> It seems the only thing that I cant keep alive is (strangely enough) Montipora digitata, which is exceedingly strange, I have had tremendous success with Acropora (even wild colonies, I have a nuclear green/yellow Acro from Tonga, which I am fragging, let me know if you want one) < :)  > , and capricornis. I did  recently start dosing Iodide, I had always used the formula GARF specifies, but Iodide was not included. I have already noted even greater polyp extension on my acros since I started dosing fractional amounts daily at Anthony's urging. <Your observations are similar to those of many other reefers- the fractional dosing is important, to establish a "baseline" for your system. Always test when you dose!> Once again thanks Tom <Tom- sounds like you've got the whole reef thing almost wired! Keep up the good work- and most of all- keep having fun! Regards, Scott F.>

Temperature vacillation of marine system Sirs I have a new set up. 100 Gallon tank. All is going well, with the exception of the water temperature.   My office is 74f and the water temperature fluctuates from 76f-80f. when the lights go on.  Please can you confirm if this is acceptable. Should I invest n a chiller unit. Regards Paul Williams <Hi Paul, A fan or two will perform the cooling/ventilation function you need to maintain a steady temp. while the lights are on. This will also save you during the summer heat depending on where you are, your summertime temps, air conditioning, etc. 80F is just fine if it is steady. Perhaps set the heater at 79-80 and time fans to come on just before lights and off after, or use a thermostat to switch fans.  I would recommend fans first, chillers are spendy and not always needed. If you are in Florida, New Mexico, Texas or Arizona without air conditioning you will want to look at a chiller.  A degree or two isn't too big a deal, but try to keep it to a minimum.  Craig>  

Salinity & Temperature Dear Bob: <Connie> I was at a meeting of SeaBAY last night (in SF area) and learned that the salinity in my LRFO tank should be at .025, also that the temperature for my tropical fish should be 80 degrees.  Do you agree?, <Mmm, most systems will do best at near seawater conditions. About 1.025 for specific gravity... and 80 F. is about right for many tropicals... but there are arguments for keeping most cooler, some warmer. You can read about these on WetWebMedia.com> My salinity is now about .022 - over what period of time should I raise it to .025, if this is correct?? <No more than 0.001 per day.> Thank you Bob. <Welcome. Bob Fenner> Connie C.

Thermometers I have read that it is not a good idea to put anything metal in a saltwater tank.  I have a 110 gallon reef tank.  I am shopping for new thermometers and have come across stainless steel and titanium types that look interesting as I am looking for more precise accuracy.  I was wondering what your thoughts were on these items and if they would release metal ions that would harm the tank inhabitants.  Thanks for your time.   Abby Kengersky <Titanium? Wow... I would select for a good glass encased thermometer and not be too concerned with absolute accuracy. More important to be precise (get about the same reading each time), that is, to do your best to measure and maintain stability. Bob Fenner>

Chilling Out! Several Months ago in summer, I purchased an Aquatherm Chiller/Heater from Flying Fish Express thinking it would maintain the chosen temperature of 77 degrees F. by merely setting the thermostat to same and it would switch as necessary between heat and chill automatically. No, you have to manually change it over several times a year depending upon the ambient temperature. Is there such a device made and finally what is your evaluation of the Aquatherm in comparison to other brands?  Thank You for your valued advice and opinions. Stephen Pace. <I personally have no experience with the Aquatherm brand. You may want to post on the wetwebmedia.com chat forum to get your fellow hobbyists' opinions on the product. I have used the Medusa dual stage temperature controller with good results. plug in your heater and chiller to the unit, and set the desired temperature. The unit energizes either the heater or chiller as needed to maintain the desired temperature. There are other manufacturers making this type of unit, too. Do check our sponsors' web sites for availability and pricing. Good luck! Regards, Scott F>

Warm Enough? Thank You, Scott. I will lower their temp. Should I keep it around 78? <I think 78 degrees is perfect!> If I have a pretty stable system how often should I be checking AM, Nitrites, PH, etc.... It is a 60 gal and we do at least a 5 gal water change weekly, but I usually only test water maybe once a month. Should I be doing this more? Thanks in advance!!! Freckleface <Well- I'm fairly conservative...I like to do once a week checks, but many successful hobbyists perform checks bi weekly with good results. As I always tell people- don't get crazy about trying to hit an exact nitrate reading, etc. Instead, look for how well your tank is doing- spot trends, note changes in formerly stable parameters. You can learn so much by following these trends! Have fun, and continued success! Regards, Scott!>

Some Like It Hot? I read in an email you had with Linlee that increased temperature is not good for the fish as it decreases their life span. Is this correct? <Well, as a general rule, warmer water temps do speed up metabolism, waste production, respiration of animals. In theory, this can increase growth rates and shorten life spans. However, the more immediate concern is the lower oxygen carrying capacity of water at higher temperatures.> I mean did I understand what you wrote. It sounded like you were saying it speeds up the life cycle of ich and all other animals in the tank... Ideally what temp should they be. I have kept them at 80 thinking it is preventing ich, but I also don't want to shorten their lives.... <Not sure who wrote that response, so I can only offer my opinions, but I think that you'd be better served in most cases keeping the tank temperature less than 80 degrees. IMO, Ich is prevented mainly by stable water conditions, including temperature, regular maintenance, good diet, and initial quarantine of all new animals. Yes, higher temps do speed up the life cycle of ich, and are a potential assist in ich treatment, but I would not call higher temperatures a "preventative", and would not keep a tank over 80 degrees on a regular basis. Other considerations include even higher potential temperatures during the day, when heat from lights can be problematic, particularly when you're already running a tank at 80 degrees plus. There are two sides to every coin, as the expression goes, so do some research on temperatures in aquaria on the wetwebmedia.com site to get the whole picture. Thanks for stopping by! Keep your cool! (sorry- couldn't resist that!)  Scott F.>

Tank Temp I recently upgraded my lighting on a 75 gal reef tank( SPS, Tangs) from 260 to 440 watts. I live in a four season climate area. Going into winter I am trying to maintain a steady temp. but having some difficulty. My tank fluctuates from 80.8 to 79.7 from day to night. Is that too much fluctuation? <No. It's actually better than the nominal accuracy of most aquarium heaters, which is +/- 1F.  Less than 1 degree isn't an issue.> The lighting unit itself has 4" fan in it that runs while the light is on. I also have a clip fan blow directly into the sump that also runs when the light is on. <You may need more or bigger fans in summer.  No worries my friend!  Craig>

You give me fever... Natural and captive reef temp.s Thanks for this. What you say below all makes good sense, and in line with my studies. But how then do we reconcile a chiller creating an artificial temperature cycle two or three times a day as it's thermostat cuts the unit in, the unit drops the temperature, unit stops, temperature rises, thermostat cuts the unit in... <Really the unit should not cycle that dramatically.> Particularly given that the variance against time is the issue, rather than the actual value (given that it is within acceptable range). Wouldn't I be best to let the tank ride the seasons variance? <This may have some added benefit, particularly if you are experimenting with bringing about a spawning event, but it would be experimental.> This would see an annual change from 26 to 32 in summer but with good stability over days/weeks. <Correct> I have bought/installed a chiller based on advice from everyone (I live in Sydney with Metal Halides), so maybe I am dreaming to think it can be kept to 32 maximum. I haven't had a summer yet with this setup so I don't know. I am skeptical and selective about taking advice on anything in this area (marine aquariums) but there seems to be a fairly consistent opinion here. Am I best to have the temperature range on the chiller set higher (say from 27 to 29) so it cycles less? <That still seems like a large range, 80-84*F.> What is the lesser of these two evils, variance or absolute? <Stability is preferable.> Any suggestions for further study (I prefer a correlation with field results  if possible). <You can always check out the National Oceanographic and Atmospheric Administration website, http://www.noaa.gov. They have data on coral reef temperatures.> Many thanks for this quite unique (conservation) resource! Michael Peters <You are welcome. -Steven Pro>

Reef Temperature Good evening/morning crew, I am coming into summer here with a 6 month old reef tank which seems to be doing very well (thank in part to some of your good startup advice, thank you :). <You are quite welcome.> I am curious to have some advice on the impact of temperature and variance of this parameter. I am running a couple of Metal Halides so they lift the tank temperature through the day, dropping again over the dark hours. My water temperature through winter has hovered around the 26 to 28 degree mark. Now with summer arriving, the temperature has moved up to the 27 to 29/30 degree mark. I have noticed that my LPS corals seem to more fully extend in these higher temperatures and also my clam. Is this a coincidence or is there likely some correlation? <Your temperature is now varying daily from 80.5 to 86*F. That is too big of a swing and too high of a peak for my comfort. Temperature swings are one of the biggest triggers for Cryptocaryon outbreaks. There is probably no correlation with your corals. Their metabolism will be higher at higher temperatures, but enlarged tissue is a deceiving thing to watch for the health of LPS corals. You must monitor calcification for an actual determination if the coral is doing well.> Does this mean they are happier/healthier? <Not necessarily.> I see a lot of writing (all?) saying that temperature must remain relatively constant around the 26 degree mark <About 79*F for us Americans.> yet I see studies on the barrier reef (Australia) which show records of reef water temperature varying between 24 degrees in winter and 32 degrees in summer months over years (and not bleaching). How is this explained? <Because this is a variation over the course of a year, not daily. My own tank does vary seasonally due to the room temperature. I have a heater set for 78*F (25.5*C), but in the summer the room temperature allows the tank to get as high as 82*F (27.7*C). I am very careful though to watch how much the temperature varies during the course of 24 hours.> I have just installed a chiller which should keep temperature between 26.5 and 28 degrees from now on, going with the assumption that stable (for any parameter) is likely to be better in the long run. <Yes> Best, Michael Peters <Have a nice weekend! -Steven Pro>

Temperature control I am setting up a 38 gallon reef that will have a few tangs. <<Mmm, not enough space for one specimen... RMF>> Without water in the tank yet, the super compacts heat the bottom of the aquarium by 4-6 degrees above the ambient temperature of the room. I just lay an aquarium thermometer on bottom of glass. If room is 70 degrees, sc's will heat to 74-76 degrees. Room is heated and air conditioned so I can reasonably expect to maintain temps of 68-70 degrees year round in room, so a baseline temp of room can assumed to be about 70 degrees. The super compacts are 2- 96 watt bulbs in ABS hood 36" long and 9" wide. It is 6" tall. This leaves about 3" on the back of tank open. The hood sits directly on top of aquarium. There is an intake fan and exhaust fan, on opposite ends of hood. The ballast is in the top of the hood on other side of reflector. Questions: 1)when tank and 30 gallon sump are filled with water, will this dissipate heat more than current empty tank? <Yes, the water movement should help to dissipate the heat.> 2)the hood has a clear acrylic cover on bottom. If I add a glass cover over aquarium that would leave about 1/4" gap between acrylic and glass. Would this help insulate the tank- sort of like double glass windows on a house?<It might help to insulate, but would also put up another barrier for the light to travel through.> 3)to help dissipate heat, should I drill some holes in back of hood? <Lets wait and fill'er up first.> 4)do you have any other suggestions on how to dissipate heat besides a chiller?<open area of the tank with a fan blowing across the surface of the water.> 5) I have 4 small pumps in sump. Two for returns to tank (Rio 2100 and Cap 2200), a Rio 2100 for Turboflotor skimmer circulation, and a small 802 powerhead for pumping water into intake of Turboflotor skimmer). How many degrees will these raise temp of tank water above the room+sc's? <Hard to say. I would fill the tank up and get everything running, let it go for a day or so, then check the temperature. If it is too high, let us know and we will work from there. Best Regards, Gage> Thanks - Mark Louisville KY

Average temperature in reef tank Bob, I have a 450 gal reef tank with chiller. Basic assortment of tangs, grammas, Chromis, nothing exotic, some mushrooms, xenia, star polyps. Am finding many different suggestions for a target temp for the tank in my research, from 75 to 80 degrees. I am now running the tank at 78,+ or - one on temp control. I was previously running the tank at 75. I increased the temp to match my ac setting, hoping to have a more energy efficient system. Tank seems to be doing fine at new temp and chiller is running half as much, chiller and sump in garage). Any suggestions, does it make a difference other than lower metabolism at lower temp? Thank you, Paul The supposed average water temp worldwide over reefs is in the mid to upper 80's. In closed systems there are other considerations like oxygen content, etc. Your current temp of 79-80F is a good compromise between the various parameters. No worries, Craig

Water TEMP. Hello guys. How are you doing today? <Not too bad! And yourself?> I've recently setup a 60 gallon tank with a tidepool 2 filtration sump and a 1200 gph pump. The water is crystal clear, I hope in 30 days, the cycle will be ready and put some fish in it. The thing I'm concerned is the temperature. The tank is 48" wide so I put a 48 inch 110 watt power compact strip light and it's on 10 hours a day. The temperature oscillates between 80 and 83, which I think it's a little bit hot. <And a little bit too large of a fluctuation for me.> The tank has no cover, just the light, and the sump is at the open so I'm providing all the aeration possible. Do you think this temperature is okay? <No> Is the variation good? <No> Should I buy a heater and adjust it to the maximum temperature the tank reaches during the day to keep the temp constant? <You should have a heater anyway.> What suggestion do you make? <I would be interested in knowing what the room temperature is. I would consider adding a small fan to blow air into and out of the stand and/or another fan mounted to move air across the surface of the tank.> Thank you very much for your time. Julio Grossmann <You are welcome. -Steven Pro>

Temperature spike Bob (or whoever is out there!) <cheers, mate> We just returned from a six day vacation and my A/C went out while we were away. Our thermometers (both reef tank and ambient temp) don't go above 86 and all were reading a higher temperature...I would guess around 90,  <very sorry to hear> As of this point, everything is still alive. The LPS corals are not looking good...mostly retracted. Until this point we were having tremendous success!  <many/most have a very good chance of survival> We did not have anyone checking on the tank because the refugium supplies a more than ample amount of food and we have an automatic water top-off device. <agreed... most tanks similarly can go towards 2 weeks easily without food if all else is stable (temp, salinity, etc)> Is there anything we can do or are we just going to have to wait and see what happens?  <do several water changes in the next week... and please let the temp fall back slowly... just 2-3 degrees per day. A fast drop my kill some animals. Also skim aggressively (get daily cup of skimmate)... there may be a lot of mucus or decay shed that will need to be exported> Thanks in advance for your help! Jonathan Bush <best regards, Anthony>  

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