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FAQs about Aquarium Chilling Small Marine Systems

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Small Marine Aquariums
Book 1:
Invertebrates, Algae
New Print and eBook on Amazon:
by Robert (Bob) Fenner
Small Marine Aquariums
ook 2:

New Print and eBook on Amazon: by Robert (Bob) Fenner
Small Marine Aquariums
Book 3:

New Print and eBook on Amazon:
by Robert (Bob) Fenner

Nano tank chilling issues       12/10/19
Dear Team
Am facing issues with cooling my Nano tank
I reside in India and am in a city which is hot and humid throughout the year. The room temperature is about 34 and the water temperature normally is about 31-32 degrees Celsius.
<Yikes; warm>
My setup details are as under:
I have two separate sumps with two chambers each.
The display overflows 40% of water to first sump holds macroalgae and DSB.
It overflows to the second sump which hosts the chiller in the first chamber. 60% of the overflow from the display falls in the first chamber.
The return pump is placed in the second chamber of the second pump which received water post skimming. The return pump is a Sicce silent 1.0 model which pushes about 900 lph to the Nano display Tank which is a 16 inch cube
<No graphic came through>
Drain 2
drain 1
Chiller Out
1 HP
Chiller Pump
Return Pump
The volume of water is as under:
Sump 1 chamber 1: 6 gallons net
Sump 1 chamber 2: 5 gallons net (sand level excluded)
Sump 2 chamber 1: 7 gallons net
Sump 2 chamber 2: 3 gallons net
Display volume (net): 15 gallons net water volume
I has a six footer aquarium previously (discontinued post relocation to another city) and a chiller for that size. Have a Hailea 1000B model suited for big aquariums. Am using the same chiller for this Nano set up
The chiller is oversized for this tank beyond doubt and chills the water within few minutes.
The chiller kicks on and cuts off way too frequently.
<Mmm; you might contact the manufacturer re changing out, replacing the controller for one with a wider on/off temperature range setting>
I am also facing challenges in maintaining the water temperature stable.
The display, Sump 1 and the sump 2 all have different temperatures even post running the chiller for long time.
<? Likely due to not much water flow through all; can you increase this?>
The chamber where the chiller outlet is situated has the lest temperature (chamber 1 sump2)
The display had the maximum temperature with a variation of 0.7-1 degree Celsius.
<This is about the most I would allow>
Please advise how I can have a uniform temperature across.
<More circulation in the main tank, more flow through the sumps>
Is it the issue of an oversized chiller cutting off and kicking on frequently?
<Might not be... and for what it's worth (esp. electrical energy cost wise), I'd get/use a much smaller (like 1/8HP) chiller here... and not use the current 1HP>
Or is the matter of flow rate from chiller ?
<Not just/only the chiller, but the rest of the system. Putting (foam) insulation around much, all the sides of the sumps might well help, but I'd just look into increasing flow in all>
I am using a pump rated for 3000 litres per hour.
<?! Well, this "should do it" here, but obviously not>
Will a smaller chilling unit provide uniformity and more stability?
<Yes it should>
Warm Regards,
Srinivas Manian
<Bob Fenner>

Chiller cooling issue- Nano reef tank      12/2/19
Hello Crew
<Hello Srinivas>
Am facing a peculiar problem with my chiller
I have a big chiller (1 HP) bought for my earlier tank ( 240 Gallons). Post my relocation, I shifted to a rented accommodation and owing to space constraints (and mobility factor), I sifted to a nano setup.
I am using whatever stuff I could from my old set-up and chiller was an expensive investment which I wouldn't have undertaken again. So am using the same chiller for a very small set up ( entire volume including Sump is about 50 gallons)
The return chamber, where the chiller pump is located, had about 3-4 gallons of water. The water is pushed to the display through by a Sicce Syncra 1.0 return pump (250 Gallons per hour)
The chiller is set to cut off at 26degreed Celsius (78 F).
The problem is that the chiller is chilling the water in the return to 26 Degrees within few minutes and cuts off.
<This is caused by the small water volume vs. the chiller capacity>
The water is slowly relayed to the display and flows through the refuge and skimmer, back to the return chamber. The temperature in the display is 1 degree more that the temperature in the return chamber.
<I suggest using a bigger return pump and/or pipe diameter; this way water will enter and leave the display tank faster and there will be no temperature variations between the sump and the DT.>
The kick off and cut off of the chiller is very frequent... say twice in 12 minutes.
<Water temp is rising fast>
Please advice where things are going wrong and how to obtain an even temperature for a reasonable time before the chiller takes care of the spike in temperature.
<Unfortunately, due to the small total water volume in your system, temperature fluctuates pretty fast and won’t remain even, for longer periods of time before the chiller has to start working again.>
Warm Regards,
<Cheers. Wil.>

High Temp.     7/31/17
Hello, this is Kim. In one of my rooms, I have a 29g macroalgae tank. So far it's only growing a baby Snowflake Eel that I'm going to give my friend. The room is decently warm in the summer although it's poorly ventilated, however the tank shoots up to 90 degrees!
I installed an air pump, fan, and I point the powerhead up at the surface. I know high temps kill fish because of lack of oxygen, not heat (unless really high).
<A combination of both...
Higher temperature results in both lower/ed dissolved oxygen and higher metabolism>
This only lowered the temp. to 86 degrees and it's been like that constantly.
<Likely okay>
I don't want to buy a chiller as I dropped so much money into this hobby (bought a 700g recently), kind of broke at the moment. However, everything is doing fine, although the eel has been swimming a lot lately. Breathes normal though. Can I keep it at this temp. throughout the summer, or would it be detrimental in the future?
<As stated, you're probably fine. I would leave the light/s off during the day, all the time (even nights) IF it's this warm>
The room cools down a lot after the
summer. Thank you.
<Welcome. Bob Fenner>

Cooling a 24gal Nano Cube  9/11/05 Hey There…  I currently work at Pure Ocean Aquatics in Littleton, Colorado during school.  I decided to go ahead and get a 24gal Nano Cube (small, but fits in my room).  I plan to make it into a reef tank… but I have a huge problem.  My room is over a garage in a house that isn't air conditioned.  My water temperature is reading at 86-88 degrees Fahrenheit. <Yikes...> So far, I've been keeping the lid open, and that helps a little (3-5 degrees), but then I can't have a light on the water (big problem if I want a reef tank). <I'd put the unit on a timer... run the lighting at night, not day> All I have in there so far is sand and cured live rock, so no big hurry.  I want to know if a "Cool Works IceProbe Micro 50W Chiller" is a decent product, <Some folks state so> and if I have any other options.  Also, I need to know how hard it is to set up, and if I should even bother drilling into the glass if I were to get an internal chiller, and so on.  I got a tank knowing water care, and fish, but I underestimated the temperature problem. Sincerely, Ben <Mmm, if you use a chiller for this tank, best to hang the plumbing lines over the side... Try changing the light cycle for a few weeks, and monitor the temperature... cooler weather is coming. Bob Fenner>

Chillin' Out (Is a Chiller Necessary for a Small Tank?) Hi There! <Scott F. here with you tonight.> Do I really need a chiller for a small 24" reef tank in my bedroom that very rarely gets to 24 degrees C? Some fishy people say I do. Others don't. I'm really confused about everything though now! <Confused?  About something in the marine hobby?  Really? hah! hah! Just kidding.  Seriously, unless you have a significant heat problem you could probably do a real good job by using a quality fan directly over the water surface.  A chiller may only be necessary in instances where your tank reaches high temperatures for sustained periods of time.> Anyway, do I need one. They're pretty expensive though and if I did need one could I do a DIY one with a fridge compressor and run the filaments through the tank? That is if even need one!! Thanks for your time anyway.  Bye, Ben <Well, Ben, quite honestly, as above, I only feel a chiller is necessary if you experience a heat problem.  Otherwise, save your money for fun stuff like salt mix, and activated carbon.  Good luck.  Regards, Scott F.>

Nano-reef chiller Hi Bob, PF again throwing in my spare change... ; ) RC has an article about using one of these Iceprobe Chillers in a HOT filter. Given that my lighting pushes my temp up to 84F(and probably over), and the fan I have to cool it blocks off the view of the tank, I think I'll be doing one of these myself. here's the url: http://www.reefcentral.com/library/reviews/IceProbe/default.htm <Thanks for this. Bob Fenner> HTH, PF

Nano-reef chiller Dear Mr. Fenner, You were very helpful in a previous question about a ten-gal nano reef skimmer. I have another question for you. I live in Hawaii, home of the coral reefs. Unfortunately, the temp (even with evaporative cooling) has been noted in my freshwater ten-gal at 82, 84, and even 86 degrees. I assume I will need a chiller for my new saltwater 10-gallon. There is a product called the CoolWork's IceProbe costing $100. It is a micro chiller that uses a cooling probe inserted through the bottom of a tank. It has been designed for approx 10 gal aquariums, and the manufacturer says that it "directly converts electricity to cooling power". Have you ever used this product, do you recommend it, and should I get one (or some other chiller)? Thank you very much for you advice <I've seen this product at a couple of trade shows (the business side of the pet-fish interest)... am concerned about the lack of a controller (you can buy, make one) with this "continuously on" chiller on such a small volume of water. If you do intend to use this unit, do secure/use a controller. Bob Fenner>

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