Re: Refugium Substrate Question   7/8/07
Thanks for the quick response Sara. Please further educate me. What "other benthic critters" will reside in a fuge, will they make their way into my tank, and, if so, what feeds on them/what are they good for?
<Worms and other benthic organisms, for lack of a better word, "stir" the sand on an almost microscopic level, keeping water and nutrients moving through the sand bed. Though some of them will probably eventually make their way to the refugium, it would help if you "seeded" the new sand with some sand from an well populated sand bed.
They feed on debris, bacteria and/or algae in and on the sand. It's thought that the larvae of some of these critters can feed corals and other reef tank life.
Best,
Sara M.>

White Critters, water striding somethings in a SW sump   6/20/07
Ok I have live rock in my wet/dry where the water intake from the tank goes/where bio balls were. Floating on top and only on top are white gnat like creatures skimming the top of the one side. There are hundreds of them and I can't get a pic of them they're too small and fast! White with wings and legs size of a pin drop. Any clue cause it's only in this part of the sump and not in the house or tank. Sorry for not much info just maybe you have some sort of an idea or heard of this before thank you.
Don V.
<... Are these insects? Not common in SW... Maybe Halobates, Gerrids... Please see the linked files in this search: http://www.google.com/search?q=saltwater+water+strider+insects&rls=com.microsoft:en-us:IE-Address&ie=UTF-8&oe=UTF-8&sourceid=ie7&rlz=1I7PCTA
Bob Fenner>

Running A Refugium for Zooplankton Production - 6/7/07
Thanks Scott!
<You're quite welcome!>
One follow up question - is there any reason to add some fish food such as flakes directly to the refugium at any time to help feed the zoo-plankton population?
Erik
<I'd be inclined to use small quantities, and perhaps even try some live phytoplankton products as well. Regardless of what you "feed" to your growing Zooplankton population, feed carefully and monitor water quality regularly. Best of luck with your efforts! Regards, Scott F.>

Copepods... a huge, diverse, important group... not all suitable for tropical aquariums for sure   4/12/07
Dear Bob (or any of the other talented staff),
<Jason>
I purchased some Tigriopus californicus - Live Copepods from reef-store.com which I found on your site. My question is I purchased the 6 oz bottle and wanted to know where to pour all of its contents.
<Mmm... an interesting Harpacticoid; with high salinity range/tolerance, other interesting bio. (amazingly large mitochondrial DNA variation w/in resident populations...), but a cold water species: http://www.racerocks.com/racerock/eco/taxalab/2005/harpacticoid/harpacticoid.htm>
I have an 180 gallon reef tank (24x24x72) that's cycling to replace my 55 gallon tank. It has been cycling for  3 weeks and although I see a presence of pods, worms and nice size arthropods it  is very few and my past experiences with tanks have been after this length of  time I typically see them flourishing and consuming the tank sand bed. I have  placed live rocks in the tank and have a 20 gallon mud sump with mangroves.  
Should I split the contents between the main tank and the refugium or place everything in the refugium.
<I'd place all in the latter... some will make their way through the pump in time to elsewhere>
I've had a mandarin for 2 years now and I do not want  him to have problems feeding in the new tank. I plan on cycling the tank an  extra week or two once I add the pods to allow them to flourish.
<Mmm, okay>
Also I have the wet/dry and the refugium as two separate entities. Both taking in their own water and pushing it out. Is this the best setup or should I find a way to plumb the two together?
<Either can/will work... I often like to suggest to keep these components individual, to allow slower circulation more easily through the refuge>
Any advice would be greatly appreciated as I've been in the hobby for 14 years now (3 marine) and I've never had any tanks remote to this size before.
<Heeeee! More fun!>
Its a 180 gallon tank (with a 1000 gph pump), 30 gallon wet/dry trickle filter, 20 gallon refugium (with a mag drive 700 pump), 3-250 MH with actinic bulbs and night lights, 20 watt UV sterilizer, 150 gal protein skimmer
Thanks,
Jason
<Thank you for sharing... Only time will tell whether the new copepods can/will adapt to your thermal et al. regime... But other life forms will definitely do so. Bob Fenner>

Re: Blenny questions--oh, and a wrasse/mandarin question! ... moving Rotifers and such, refugium biota...  – 04/11/07
Thank you so much for the good news!!!
At the risk of sounding completely incompetent, how exactly should I  retrieve the rotifers, etc from the refugium?
<Perchance a siphon>
I moved some Caulerpa, but there isn't much in there. There are a bunch of little critters on the sides of the fuge, but I don't really want to scrape them off....?
Also, my LFS said the six-line must go because he will hog the rotifers from the mandarin, so I will move him to the 150 and pray that he is too small and beneath the ornate wrasse's notice.
I will move the blenny, too but I am probably going to have to dismantle the smallest nano tank to do it.
Thanks again.
<Welcome in number. B>

Getting Critters From the Refugium to the Display – 04/05/07
Dear Crew Member,
<<Hello Chris>>
Thank you for so liberally giving your time to improve the hobby.
<<Is a pleasure to assist>>
I am contemplating an upstream refugium.  I will pump water from my main display and have a gravity return from a drilled glass refugium.
<<Neat>>
Here is my planned configuration:
40 gallon drilled breeder display tank with soft coral and 3-4 small, non-aggressive fish.
30ish gallon gravity fed sump below tank for skimming, heating, top-off, a deep sand bed and Chaetomorpha harvesting.  30+ gallon upstream refugium (36x18" footprint) with lots of live rock for pod growth, to reduce the need for adding food to the tank and for my visual pleasure.
<<A few things worth mentioning here...  Don’t expect the addition of the refugium to take the place of proper feeding of the tank, you still need to feed the fishes/corals adequately and on a regular basis.  Do look to the refugium as a means to supplement natural/live prey items, just not as a “replacement” for feedings.  And do think of the refugium as “more” than just a food source.  Adding the refugium provides a biological niche that is often quickly overwhelmed in the confines of the display.  The added biological diversity all helps with achieving/keeping the system in “balance.”  I also want to give you something to think about in regards to the setup of the refugium.  I suggest you place the DSB/Chaetomorpha in the refugium, and place the rock in your sump.  The larger space in the refugium will be of more benefit re the sand bed and macroalgae, and since the rock doesn’t require lighting, you will help avoid growing nuisance algae in your skimmer/sump by moving the light to the ‘fuge.  And don’t be fooled, the dense matrix of the Chaetomorpha is excellent habitat for housing populations of “pods,”  worms, etc.>>
My first instinct is to drill the top of the refugium tank wall and simply let the water gravity-flow into the main tank.  However, I typically notice amphipods and copepods swimming/crawling lower in the water column.
<<They do get “all around.”  I’ve often seen them around/on the bulkhead screens where my refugium drains to the return-pump chamber in my sump>>
Will enough critters make their way to the main display from an overflow high in the refugium wall to make a nutritional difference?
<<Not as a direct replacement to feedings/not without the refugium being many times larger than it is...regardless of how it is plumbed>>
Is there a better plumbing option to have pods make their way to the main display.
<<Not really...without risking siphoning the refugium dry in the event of a power outage.  In my refugium, I have found moving the Chaeto ball up against the drain bulkheads puts more critters in close proximity as they travel through the algae matrix>>
Regards,
Chris
<<Cheers, EricR>>

Small Refuge Setup for a Nano-Reef, subst. biota  3/27/07
Hello Bob ... greetings from Manila, Philippines.
<And to you my friend, from Hawai'i's Big Island>
I've spent many hours reading your FAQ's .. so much great information on your site.  Thank you.  I hope you'll have time to answer my questions.
<Will try>
I'm setting up a 20-gallon tank, first FOWLR then moving into SPS.  I plan to go skimmerless.  I'm planning on a 5.5-gallon refuge.
<Okay>
Given that I'm going skimmerless, do you think I at least need a 10-gallon refuge, or can I get away with 5.5-gallons?
<"The bigger the better"...>
Also given that it is a small tank, 14" tall, I'm planning the following: 2-inches Miracle Mud on the bottom, 4-inches sugar-fine sand, 2-inches crushed shell on top.
<Mmm, I encourage you to somehow partition the "Mud" from the calcareous substrates... maybe with Siliconed glass partitions.>
This leaves less than 5 inches for my water space/Chaeto.  Is this water space too small?
<Mmm, no. Not too small>
I know your a fan of DSB's, but with a small tank, is this deep enough to encourage denitrification?  Is this the correct order and depth?
<Yes and yes>
I've read about methane pockets that can occur in DSB's which crash systems.  Some people stir up sand to release any small forming gases.  Others feel that the sand should not be disturbed as it will interrupt the denitrification process (I think this is your stance).  If I choose not to disturb the sand, how will I deal with methane gas pockets?
<I would not disturb this sand bed>
Is it a good idea to have any other critters in my refuge: i.e. hermit crabs
<Mmm, no... are too predaceous>
for any detritus, or larger brittle stars for sand movement?
Regards,
Jason B
<I would leave these in if they were natural recruits... but otherwise just count on incidental recruiting of various invertebrate infauna from your live rock in the main tank here. Bob Fenner>

Urchin in Mud Refugia/Sump Area?   3/1/07
Dear Bob,
<Actually Adam J with you tonight, hello.>
Can a pencil urchin survive in a mud sump environment.
<Urchins are largely rock dwelling in nature, but with some rock for hiding, etc.., a light and food source I don't see an issue. Though I would surmise it would partially be an unwanted organism in any type of refugia. Not only being clumsy and destructive but being an opportunistic omnivore, feeding indiscriminately on algae and other benthic life forms.>
I have a lot of algae growing in there
<Why are you concerned with algae in your sump/refugia area...is this not it's designation...would rather in colonize here than is the display or this refugia intended for other types of life?>
and could use the hitchhiker to keep it clean,
<If it is filamentous algae, smaller less destructive herbivores such as small snails would be a far better choice.>
Also will the Aiptasia anemones harm the urchin?
<No, though a large population of Aiptasia is usually indicative a larger nutrient issue.>
Best regards,
<To you as well.>
Jason
<**AJ**>   

IPSF starter kit is in the refugium -- will residents starve? Feeding Refugium Residents and Other System Tweaks!   2/23/07
Fellow WWM mariniacs,
<A very appropriate title! Scott F. here tonight!>
I just built a 20 gallon sump/’fuge to go with my 30G display.
<A nice boost in size!>   
  ‘Fuge info:
+  Mag 7 for return through ½” PVC40.  (24” rise, or so, out through ½” street els, GPH unknown, but seems to move well).  Terminal street ell drilled with small hole just below water level to minimize siphon-back on power outage.  One union for disassemble and cleaning.
  +  About 7 lbs small live rock fragments in one compartment,
  +  6” ~1.5mm aragonite DSB in another section,
  +  Separations are the sliding acrylic baffles with the rubber weather stripping.  
  +  ‘Fuge also has Prizm Pro skimmer, 220W stealth heater.
  +  Got the Mix N Match Kit from IPSF and seeded with ‘fuge starter stuff – bristle worms, mud, clams, snails, tang red, tang green, ‘pod kit.
<One of my favorite e-tailers. I highly recommend them>   
  The 30 glass display has:
    +  Two yellow-fin damsels, Lenny and Squiggy
  +  Pseudochromis Diadema, sponsor of state terror
<Sounds delightful!>
  +  Shapely and colorful green Actinodiscus perched on rock maybe 10” from lighting, dead center under actinic lamp.
  +  Fat and happy blue Actinodiscus with babies nearby  (perched higher than green, maybe 6" from lighting)
  +  Blue mushrooms are surrounded by some green and yellow zoanthids that came along for the ride from the store.
  +  Emerald crab, maybe ¾ inch diameter carapace.
  +  Small miscellaneous hitchhiker crab, blackish and meek.
  +  Four small hermit crabs.
  +  CPR 90 overflow (with Aqua Lifter) from Marine Depot (hums like a butterfly, stings like a bee) – 1” PVC40 overflow back to ‘fuge.  Two unions for cleaning and a ball valve—Noisy, baby.
  +  About 35 lbs live rock, arranged in triangular aquascape, peaking at left with blue ‘shroom and zoanthid rock at the top about 6” from the lights, and defining an open area in front.
  +  30” Coralife, two bulbs, one actinic, one white.  Standard fixture, not sure the lumens.
Feeding is now, three times per week:
  +  One cube of frozen krill mix, thawed in nuke oven, crushed into bits, strained, then gingerly dropped bit by bit into the display.
<Careful feeding technique. I'd skip the microwave part, though. You don't need to do that, and it might even change the nutritional profile, for all we know.>
  +  Pump off, then four drops of concentrated Zooplankton (Kent) mixed in cup and added in area of mushrooms.
  +  Maybe 20 drops of Phyto food liquid from store (Kent again) dropped in vicinity of mushrooms / zoanthids.
  +  Pump off for one hour.
<Do be careful with these liquid foods. I have some reservations about non-living liquid foods, especially those that are not shipped/sold and stored in the refrigerator. They may degrade to the point of being simply pollution in a bottle. Study them and do consider living alternatives.>  
  Periodic supplements:
  +  Ten drops iodine once per week.
  +  Chalk water from Germany (Kent) “the best calcium supplement by far!” (could the directions for this thing be any more Teutonic?) -- added from clear liquid on top of mix in bucket at maybe 4 ounces per day.
<Both are useful supplements, but they should be added according to your system's requirements. If testing dictates the need to add iodine, in particular, then go for it. Otherwise, there is a potential for inducing algal blooms, particularly in smaller systems. Your best "supplement", IMO, is a water change!>   
  Parameters:
     +  PH perhaps 8.2 / 8.3
  +  Specific gravity at 1.024 or so.
  +  Ammonium = 0, Nitrite = 0; Nitrate < 5ppm.
  +  Phosphate = 0.
  +  Calcium at maybe 300 and rising.
  +  KH at 12 drops – is that around 180 on the scale (I do not recall)? Anyway, I think this means good buffering capacity.
  +  Magnesium and Strontium unknown.
   <Parameters sound okay.>
  Lumination schedule:
     +  Display:  12 hour cycle 11am to 11pm.
  +  ‘Fuge:  was on opposing schedule 7pm to 7am, but I left it on all day and night yesterday thinking my IPSF residents had light-starvation jet lag from Hawaii.
OK, finally now, I can raise some questions and concerns.
  Issue one:  I have become slightly alarmed by some of what happened when I dropped by IPSF package into the ‘fuge.  
  Worms.  Many of the worms from the mud and bristle kit quickly followed a flow into the pump area, made it through the pre-filter black microphone cover thing into the Mag 7, and became wiggling bait for Lenny and Squiggy and their bully overlord in the display.
<Bummer...>
The bristleworms seem to have arrived bleached and dead.  No red hue apparent, and anything with bristles appears to be dead meat and settled on top the DSB.  The spaghetti worms from the wonder mud mostly appear to have met the fish food end in the display.  Those that remain seem disinterested in the 6” substrate, which I find bizarre.  Could it be my DSB is too young and virgin to provide food for these guys?
<Well, if their natural tendency is to burrow, they will, eventually. I'd give it a little more time to happen.>
If so, should I buy “Mama mia” worm kit from IPSF a little later down the line once the DSB is more compelling?  DSB was topped off without about 1" established sand from the display, over which the IPSF mud was dropped.
<This should work for now. If you think that you had some DOA's, do bring this to the attention of Gerald Heslinga (owner of IPSF). He is a great guy and will stand behind his products.>   
  Tang Red and Tang Green.  Beautiful stuff, but the red is making its way around and over the acrylic lined baffles in the ’fuge, where it collects on the pump pre-filter thing and makes it look like a red Christmas tree or a game of pickup sticks gone horribly awry.  I fish it out with gloves on and put it back in the main area, but it will find its way back.  What to do?  I fear clogging the pump.
<I'd buy one of those small straining colanders- like the kind you use for vegetables or rinsing rice. You can find small ones at some discount stores. You can place the Gracilaria (that's the species of macroalgae known as "Tang Heaven") in there. It likes a little motion- in fact, it likes to be tumbled, so you can place it where it will get some current, or you could even place an airstone in your "algae colander"!>   
  The tang green looks like lime flavor fruit rollups.  Is this Ulva stuff going to grow from this form?  It seems like maybe I have part of a plant, hard to see any distinguishing features, reproductive organs on this stuff.
<Hard to say, really.>   
  Nutrients.  Are my new ‘fuge dwellers going to be happy with the nutrient input from so little livestock in the display?  Do I need to give them more nutrients as they get settled in?
<You'll be surprised what they find to eat in even the "cleanest" systems. However, if you are concerned, you could always provide some extra food for these creatures (carefully, of course).>   
I installed the ‘fuge as a last ditch attempt to eradicate Cyanobacteria and banish it from my lexicon for a while.  Now, I’m worried I might have set up a ‘fuge that will starve, then I will be back to a Cyano problem.
What sayeth the great Oracle of all things aquatic?
<Well, no great oracle here, but I am a fish geek who has fought the nuisance algae battle many times over the years. I'd think about the possible causes of your nuisance algae problem. A big contributor to these outbreaks is excess nutrients caused by overfeeding or indiscriminate use of additives and liquid "foods". You sound like a very dedicated and careful hobbyist, but I'll bet that you could skip those additives with more frequent water changes, and I'll bet that you won't need to feed those liquid foods. Keep up your water quality monitoring, and good overall husbandry practices, such as aggressive protein skimming, and ,maybe run some activated carbon or Poly Filter media in your system on a regular basis. You might be surprised how quickly things turn. Other than those minor adjustments, you're doing fine. I often find it useful to remember the wonderful advice given by author John Tullock in his book, "Natural Reef Aquariums": Test, then tweak!" It holds true for almost any system...Don't add stuff to your tank if testing hasn't dictated its necessity. I'm sure that things are gonna be just fine! Good luck! Regards, Scott F.>

Clean Up Critter For Sump 2/9/07
Hello Crew,
<Hi Chad>
I have a quick question for you; I have a 20 gal sump that is hooked up to a 46 gal bow front reef tank and a 29 gal refugium.  My overflow sucks in food periodically when I feed my fish.  I would like to put a critter in the sump to eat the left over food. I have another reef tank, 120gal with a 30 gal sump that I put a few black mollies in to eat the leftovers and that seems to work out fine, although the lights are on 24/7 because of the macro algae growing within it.  In the 20 gal sump it is dark most of the time except some indirect light coming from the reef tank above it.  I'm thinking of an arrow crab for the sump instead of a molly because most of the left over food is meaty. Is this a good idea or do you have another critter that would work out better?  
<I prefer invertebrates over fish for clean up work.  Fish add to the bio load of the system.  An Arrow Crab would be fine for your purpose.>
Thanks,
<You're welcome.  James (Salty Dog)> <<Invertebrates add to the bioloads of systems as well... RMF>>
Chad

Re:  Clean Up Critter For Sump - II - 2/9/07
James thanks for the reply.  This raises another question though.  By saying that the fish (mollies) in my sump add to the total bio load (I do agree), you mean the use of oxygen and the production of ammonia.
<Yes.>
Do invertebrates (an arrow crab in this case) use less and produce less therefore add less to the total bio load?
<Yes.>
Thank in advance for the further enlightenment.
<You're welcome.  James (Salty Dog)>
Chad

Refugium Safe Sand Stirrers - 07/13/06
Hi my salty friends.
<<Hello Stephan>>
I have a 55 gal. cryptic refugium with live rock,  5" DSB with 1-2 mm sand.  I'm running a 400gal/h pump thru it.  It is lit at night with an actinic light for 12hrs.  I noticed that my DSB has clumps of sand in the upper layer.
<<Hmm...overusing calcium/alkaline additives?>>
I was wondering what sort of animals I should add to help stir things up?
<<Mmm, I'll get to this in a moment>>
Is my flow too low?
<<No>>
Is my sand too coarse?
<<No>>
I don't want to put anything that might eat my pods. Help!
<<And therein lies the rub Stephan.  Anything you put in the refugium to "stir" the sand will be eating some portion of the biota contained within...even snails!  Heck, your "pods" will even prey on their young if the available food supply gets low enough.  But, adding a dozen or so Nassarius snails or Cerith snails won't decimate your pod population (I have Nassarius snails in my own refugium) and are likely your best bet in this instance.  Do be sure to stay away from sand-sifter gobies and the overly efficient sand-sifting starfish>>
I appreciate your generosity with info.
Stephan
<<Am happy to share.  Regards, EricR>>

Refugium Setup 5/29/06
Hello.  
<Hi>
I have been reading your articles and forums about the benefits of fishless refugiums.  From my understanding they create a breeding ground for various pods and zooplankton that feed the corals and fish in the display tank. <Yep> My question is, by "fishless" do you mean no fish, or no large animals altogether?  I recently learned that serpent stars and hermit crabs are very rough on the pods which inhabit the sand bed, often destroying them completely.  For my future refugium, should I leave all cleanup crew members (blue legged hermits, Turbos, emerald crab, serpent stars) out, or is a fishless refugium simply without fish?  Thanks
Jon
<A better way to describe it is to call it a predatorless refugium, but it doesn't sound quite as nice.  But no, I would not add any crabs or stars to the refugium.  Just rock, water and macroalgae if you want it.>
<Chris>

Lobster/Macro Algae Refugium?  5/11/06
Dear Crew,
<Hello.>
Long time reader, first time poster!
<Awesome.>
Great site, it has helped me in countless ways with my new salt water venture.  
<Great to hear.>
My question is:
<*Drum-role please.>
I have a 55G tank and I am looking into converting a 10G aquarium I have set up that currently exclusively houses a Purple Lobster into a refugium.
<Cool.>
(He was put there based on recommendations I read in your FAQ's, plus I was losing fish, & I came home from work one night to see him munching on my coral banded shrimp!)
<Not uncommon.>
  My question is, is it OK to convert this tank into a refugium and still let the Lobster live in it?
<No, defeats the purpose of the pod-generation, not to mention he will be destructive to any macro-algae you put in there.>
The purpose of the refugium is to help lower my Nitrates which hover around 10 PPM.  I plan on the 6" DSB and Chaetomorpha, per other FAQ suggestions I have read.
<Yeah.. if that's what you want get rid of the lobster.>
Thank you for your time, I have spent many hours perusing the site and, like most people, have found MANY answers from the FAQ's.
<Great.>
Thanks,
<Anytime.>
Craig
<Adam Jackson.>

Xenia Scrubber/Refugium - 05/10/06
Hi Crew! I am in the process of redoing my refugium (9" x 12" area in my sump) and I think I want to try a Xenia scrubber rather than Chaetomorpha or similar macro.
<<Neat!  I set up one of these for a short time a couple years ago>>
My question is regarding lighting.  Currently I have a 6500K 13w PC over the fuge which worked fairly well for the macro.  I am looking to upgrade this lighting and have come across two setups that I cannot choose between.
1. 70 watt metal halide retrofit kit (10000K bulb)
Or
2. 2 x 32 watt power compact retrofit kit (two 6700K/10000K bulbs)
My main goal is to grow the Xenia FAST and remove nutrients from the water.  I also thought that if I went with the 70w halide I could place a few small frags in there while they are awaiting final placement in the main tank.  Any thoughts?
<<Yep... Either lighting scheme will suffice, simply choose that which you prefer/is more cost effective to install/operate.  My 29g Xenia refugium was lit with a single 65w 6500K PC bulb and it grew very well.  I have also maintained shallow SPS frag systems under this same lighting with good results.>>
Pleasure as always. J
<<Regards, EricR>>

Sponges In My Sump For Filtration? - 01/19/06
Hello,
<<Howdy>>
I will be having a DSB in an unlit sump and wondered if there were any sponges I could put in the sump to help filtration?
Thanks,
Ben
<<With few exceptions sponges don't usually fare well in our little captive environments, and a large sponge gone "bad" can do real damage (poisoning).  You're best bet is to employ the encrusting and cryptic sponges (Diplasatrella, Monanchora, Phorbas, Spirastrella) found on/in live rock.  Place a few pieces in the sump and those sponges for which the conditions are right will develop and grow.  Regards, EricR>>

Mud/DSB/Refugium  11/15/05
Good morning and thanks as always for your willingness to share your expertise.
<Welcome>
I have now setup up my brand new system with a 4-5" DSB (Aragamax) in the 90G show tank, and a 6"+ DSB (Aragamud and Southdown) in a downstream refugium. I plant to put macroalgae in the refugium, and seed both DSB's
with critters- live sand, MiniStars, etc. My question is the ORDER I should do things, with this brand new system. 
<Okay>
A) First, since it is not an established system, can I/should cure my LR in the tank? 
<I would likely do so... if this was the only/best place... or you had no other, yes>
B) Should I buy macroalgae and/or critters first and establish the live sand in the DSB's, or put in LR first?
<Better to wait on these till ammonia, nitrite are absent, some nitrate accumulating>
Unsure if the LS should be there to help with the in-tank curing (if that is recommended), or if the curing process
would just kill the infauna in the sand?
<Mostly the latter>
C) Maybe just the macroalgae first for nutrient export?
<Mmm, no, best to wait on this too>
I am sorry if this is covered elsewhere, there is so much information now (which is great) that it is not that easy to find specifically matching questions. Thanks in advance for your thoughts!
Regards,
Bob Lee
<Thank you for writing so clearly, completely. Bob Fenner> 

Refugium question
Aloha Mr. Fenner,
mike here, i had a question about live refugium starter kits. i
currently have a 30 gallon reef system with a 15 gallon refugium/sump.
my tank has been up for about 2 yrs now.  my only filtration is a
small Penguin Biowheel filter and a Seaclone 150, it seems to be
doing an alright job.
<Fine for this size system, with good care/maintenance overall>
(i was going to pick up a Georeef skimmer cs6-1,
i also wanted your opinion about overskimming).
<No need to switch here>
the starter kit i was
interested in was the inland aquatics flora and fauna kits. they can be
found here http://www.inlandaquatics.com/prod/prod_refu.html .
<Ah, yes. Know the owner/manager, Morgan Lidster. A fine fellow>
would
you suggest using this product to boost ones refugium?
<Yes>
do you have
other suggestions for a more natural type of biological filtration?
<Mmm, the periodic trading out of substrates (rock, sand...). Not easily done in Hawai'i.>
I'm
afraid the types of algae included in the kit may try to reproduce and
cause my tank to crash (the Caulerpa algae mainly). i have already
spoken to the personnel at inland but i just wanted a second opinion.
your opinion and suggestions are greatly appreciated.
Aloha
mike
<Considering your success, apparent good care, powers of observation... I would not be concerned re one type of algae over-populating this bit of water. Keep trimming it and you'll be fine. Bob Fenner>

Mussels in a sump
Hi WWM Crew,
<Hello Chris>
First I would like to say what an excellent site you have, it has been an endless source of useful information to me since I started my marine aquarium last year. Keep up the good work, the hobby would be a lot more difficult without you!
Now that the flattery is out of the way, to my question. I have been feeding my chocolate chip starfish live mussels which he/she loves and I buy in 1kg bags from the local supermarket. Last week as an experiment I placed one in the overflow box to see if it would live, if not it would be easy to retrieve before it died and polluted my system (a LFS told me that these can really pollute a system if left to rot after they die, is this true?).
<Very much so> 
I expected it to die as they are collected from the Orkneys North of Scotland, where the water temperature is significantly lower than the 28C of my set up. However after a week it is still alive, openly filtering water and reacts very quickly when touched by closing up tight. This lead me to think would it be possible to put the kilo of mussels in my sump firstly to give me a long term supply of live mussels for feeding the starfish and secondly, would there be any advantage from the filtering effect of having 40-50 live mussels in the sump?  I am intrigued to hear what your thoughts are on this. 
<You have a few things going against you in this regard. As you say the temp is significantly lower where the mussels are collected from, so more than likely the warmer temp will not be suitable for them. Secondly, they are strictly filter feeders and the small amount of nutrients they get from your tank is certainly not going to sustain them. Then, as your LFS says, if one dies without your awareness, the problems that causes is not going to be worth the risk. If your interested in keeping them alive for a food source, I would put them in a tank by themselves, unheated. You would still have to provide phytoplankton for them to survive long enough to be used as food, and now we are getting into cost effectiveness of your end product. The choice is yours, Chris. James (Salty Dog)>

Refugium
Dear Bob, Anthony & Staff,
Thanks for all your help! My tank has improved so much since I found this site and your books. My problem is now things are growing too fast (especially my Xenia) I have given a lot away but they still grow back on the spots of the rocks were I cut them off. They truly are like weeds. My question is I have recently added a refugium with a DSB & Chaetomorpha (after reading Anthony's book) Do you think it would add any benefit to the refugium if I started to stock it with the Xenia? Thanks again. 
<I think it would be very insignificant. James (Salty Dog)> 

Refugium - Stocking 04/25/2005
Hi,
I have a 72 FOWLR and have a bit of a nitrate problem (< or = 40 ppm) and bought a hang on refugium from eBay (12 x 18 x 4 inches - only $35 shipped!) basically a generic CPR one.
<Hey nice hardware.>
I have an extra 32 watt PC (actinic/10,000 K) that I plan on using for the refugium, is this too much light?
<I think that light will work nicely>
Also, what type of Caulerpa do you recommend?
<There is a lot of discussion on this and the most popular macro seems to be Chaetomorpha. Fast growing and will not go asexual which is the rumor on a lot of Caulerpa>
Should I put red mangroves in? I've hear they do a good nutrient export job, which is strictly what I am looking for.
<Mangroves, which are nice, take some room to grow and Chaetomorpha is much easier to grow with this setup in my opinion>
Should I put a sand bed, use mud, or go naked / bare.
<This is all based on what you want to keep.  Because this is a fish only that will depend on the food requirements for those fish.  Amphipods can be grown with a larger substrate while copepods like a smaller particle size.. It all depends on what you want to harvest.>
All I'm looking to do is improve my water parameters, the refugium isn't for looks as it's behind the tank. Oh, and one more thing - should I be running the lights 24/7, a reverse schedule of my main tank, or something else?
<A lot of people have success with 24/7.  A good reason to run a cycle that is opposite your main tank is to help stabilize PH.  So I would recommend the latter of the two.>
Thanks so much for the help!
<Anytime.. EricS>

Populating a refugium + importance of ALK + Calcium testing
Hello,
<Hi there>
I have been reading your Forums for a couple of weeks now and am set aback
at the amount of information.
<There is... much to know, relate>
I used to run a LFS and went out of business because I was too honest (I was
not moving the junk/gadgets).
<Hee hee! More important (of course) to be yourself... not gain the world and lose your soul...>
I consider myself an intermediate level reef keeper - I know a lot but not
hardly enough ;) .  OK, on to my questions:
About my system:
55 gallon Reef - In wall installation accessible via closet.
75lbs of live rock
DSB 3inches 4 in places
Tunze Skimmer 3110/2   *Small I know  :(  I may DIY one, I have an old
Seaclone I would like to Mod.
<Maybe for experimentation... I'd stick with the under-sized Tunze>
2x refugiums, one is sump/fuge combo 20gal - the other is sump/fuge combo
25gal driven by one Mag Drive 350gph.
Temp 73
PH 8.3
Ni Am = 0
Na less than 10 ppm
Cal?
Alk?
2x 802 powerheads
CPR overflow
Fluval 302 running carbon only
Lighting - Giesseman 350watt 10000K
Livestock: 2 Domino Damsels - 1 Sailfin Tang
<Hard to add more with those Dascyllus present>
20 snails/20 hermit crabs
1 BTA  (MIA)
2 cleaner shrimps
1 peppermint shrimp
1. I hear everyone talking about all the cute little bugs in their refugiums
- How does one *populate a refugium?? Does it just happen by itself? How do
I get all kinds of critters in there?
<Can add directly (as in a "kit", e.g. from IPSF.com, InlandAquatics.com...) or the self-producing LR route>
2. Can I have only micro Algae in the refugium or should there also be live
rock?  both refugiums have DSB's.
<Better to have LR and macroalgae...>
3. If I am using store bought water form a Winemaking store (completely
demineralized)  + instant ocean, and a 10% water change once per week,
should I still have to watch my calcium levels or should they even out?
<Likely will be okay... is there something "that wrong" with your source water? What? I would get/use test kits for Calcium (though not Magnesium Strontium) and alkalinity if you were/are concerned>
*I have good purple coralline growth*
<Bingo! I would not worry re the above>
4. What is the importance of checking the Alk levels?
<Mmm, another "window" on what's going on, might go on in ones system. Many folks, mainly due to over-crowding, over-feeding, lack of maintenance have shortfalls of alkaline reserve... suffer further troubles in algal proliferation, livestock health as a consequence...>
5. I have been having problems with algae in the display tank (the reasons I
recently installed the fuges) I have been told it is red slime algae, but it
looks brown - It covers everything in it's path - heck it even grew on my
Yellow Cuke. It looks like an old opaque spider's web.  I cannot understand
what is causing this... any hints or things to look out for?
<Cyanobacteria/BGA can be any color (is it slimy?)... with time, the refugia will clear this up... I would not be concerned>
6. On a side note - I bought a BTA about a week ago and he seems to have
disappeared.
<Happens... if "unhappy" can scrunch down to a very small zot in size>
I thank you in advance for all information/help/pointers/tips you may offer.
<Glad to share>
PS Where do I see the answer to my questions once you answer them - do I
check in the Forum?
<We send all back to queriers, and later post to the Dailies, then later to separate FAQs files. Bob Fenner>
Robert Martin

Cheap refugium setup 1/16/05
I have just finished setting up a refugium/sump for my 55 gallon tank and thought others might wan t to know of how cheap it can be to jump start the invert and critter growth in one.  I bought 2.50 worth of live sand and asked for the detritus from the live rock tanks while they were getting my sand, they dredged out a bag full  (around 3 pounds) and gave it to me free as well as some Caulerpa that was in the tank.  This "gunk" is loaded with everything you need and it comes in the correct size substrate as well.  I did some checking as well and most fish stores are not only willing to do this for you they are happy to clear the crap out of their LR tanks as it is generally an eye sore for business.  so don't hesitate to ask, you never know what you might get for free.
<an interesting refugium strategy... thanks for you input. Anthony>

Snails and refugia 3/17/04
Hi there, thank you for your help, I love reading the files.  I also adore my copy of Reef Invertebrates, it's on my night stand as a semi permanent fixture.  I have two questions I haven't been able to answer in my reading.
<outstanding... thanks for saying so>
First, we seem to have baby snails in both our larger salt water aquarium as well as our 12 gallon eclipse which is presently (for the last three months since set up) housing inverts with a few soft corals and fern Caulerpa only.  Both tanks have a mixture of Astraeas, margaritas, Nerites, bumble bees, Nassarius, and Ceriths with the Nerites and Ceriths being the predominant species which has solved our algae (diatom on glass) problem.  
<the Ceriths in particular are excellent and reproduce readily>
These snails look to be either Astraea or Nerites in type, they are so small, though plentiful.  I understand that the Astraea snail has spawned in captivity, but survival to a shelled form, is it possible?  
<not possible/practical for their long larval cycle>
Or is this a live rock hitchhiker (larger tank is 60 gallons and has been in operation for more than a year.)?  
<yes... quite likely>
We have seen these snails in both aquariums and another variety on the invert tank that looks a lot like a baby Nassarius snail. In our larger tank we house a pair of tank bred Banggai cardinals (along with a six line wrasse, a dwarf pygmy angel, two false percula clowns, and a royal Gramma Basslet)  I understand that the cardinals do not do well on flake food and we would like to take a vacation this summer.  
<if they presently eat flake food... then the vacation is no trouble at all. If not, most fish can still easily withstand a 5-7 day fast>
Would buying a Mysis shrimp starter kit  (the shape is hexagon, a refugium won't work, we already tried the hang on the back model with a steep increase in nitrates and deterioration of water quality.) help them to be able to eat during this vacation and to go away for the weekend in the future?  
<yes... excellent>
Or would they be eaten up rapidly?  
<do revisit the passages in our reef invertebrate book on zooplankton reactors (in Refugium chapter) and seek to produce them continually>
The supplier is Inland Aquatics.  
<Morgan Lidster at InlandAquatics.com is a great guy. Very knowledgeable, honest and a credit to our hobby/industry>
Thank you for your help, and again, great book!
<thanks kindly, Anthony>  

Crabs in refugia? Best not to 4/20/04
Hello Anthony,
<cheers, Drew>
thanks for the reply. Would these crabs do well in a refugium used to grow macro algae?
<not likely my friend... when refugiums are best employed as plankton producers and nutrient exporting devices, the inclusion of predatory creatures like fish, shrimp, crabs, corals, etc is not recommended because their inclusion is a net burden on the system. In a phrase: they take more than they give, in refugia. They require an import of nutrients (feeding) and/or they deplete more desirable microfauna (worms, microcrustaceans, etc) that they can/will prey on>
I am very new to marine so still learning and getting new
ideas, was thinking of having a refugium with live sand and some live rock and light with lights to promote algae growth, is this the right idea behind a refugium,?
<yes... this is one possible way to run a refugium. Let me encourage you to read our chapters on refugiums, plants, algae and live sand/rock in our Reef Invertebrates book. It is the most current and comprehensive information to date (about 100 of 400 page book)>
Thanks again. Drew
<it looks like you are in Canada, my friend... if so, you might check with the following distributors for our books and others:
Best regards, Anthony 

Feeding His 'Fuge! (Refugium Life Forms)
Hi all,
<Hi there! Scott F. with you today!>
I have a 90 gallon reef system that has been up and running for 7 months or so. As to the advice of many I set it up with a 40 gallon above tank fuge. I stocked it with a DSB ( as well as the main tank). I also placed many spaghetti worms /amphipods. rock rubble ...live sand etc.,  from IPSF in Hawaii.
<My personal favorite e-tailer!>
My question is that, while I do see a great deal of pods and worm type crevices in the sand, I am not sure that they are actually getting downstream to the main tank. I have kept the main tank fishless for the whole seven months (one algae blenny to help initial algae bloom ) in order to develop a healthy population of pods. There is some green Ulva in the fuge as well . Any advice as to getting these bugs to go downstairs to the main tank. The fuge does overflow into main tank, but I do not think they are getting there.
<I'll bet a fair number of them are getting there. You may want to look at night, after the lights are out. I suppose you could also engage in a rather tedious "manual transfer" of these guys by net, etc.>
Also, I never actually see these worms but I do see burrows in the sand. I assume this is from there presence.
<Yep...You don't see tem too often, but their "burrows" and "castings" betray their presence>
Also any advice on feeding the fuge critters?
<Well, nutrients and food from the main system will usually do the trick. You can also "feed" the life forms in the refugium directly with some finely-sized frozen foods, like Cyclop-Eeze and the like. Regards, Scott F>

Animal Filter - 12/22/03
Hey there Anthony!  
<howdy Eric>
I have a question regarding the use of an animal filter, which I recall you discussing in your book.  
<yes...>
I'm using a 55gal. AGA for a 'fuge which has a 6" sugar-fine sand bed and Chaetomorpha algae.  
<excellent start>
I had planned to install a second 'fuge as an animal filter with Anthelia and Xenia as the "living filters".  As luck would have it; no room for the second 'fuge so I wanted to get your take on utilizing both methodology in the same container?  
<its never a good idea. Mixing plants and animals in culture in any combination will not allow both to thrive optimally. In this case... soft corals and plants more than most any other critters on a reef are competitive and can be very noxious to each other>
As long as I provide a partition for physical separation, are these species (Xeniids and Chaetomorpha) low enough on the "noxious scale" to effectively work together without battling each other to the detriment of the system?  Happy Holidays.  Eric
<there is not scale of measure that I am aware of between animals. Just studies on relative toxicity and noxious exudations by individual. Regardless... the practice of mixing the two is generally a bad idea. IN this case, with the partition and considering the nice size of this fuge... I'd be willing to see you try it. Neither organism individually is known to be especially bad (they are generally regarded as weakly noxious). DO let us know how it works out. Best of luck, Anthony.>

Hitchhiker ID/Refugium/Snail reproduction - 2/26/04
Hey Crew!
Thank you all for such a great site.  I wouldn't have made it this far without all of you. <We wouldn't have made it this far without your questions. So, thank you>
I have attached an image file (not the best picture in the world) of a hitchhiker that has shown up in my tank.  If anyone has an idea of what this is I'd greatly appreciate the knowledge. <Definitely an anemone from the family Actinodendronidae See here: http://www.wetwebmedia.com/anempt2.htm>
My second question, is it okay to keep hermit crabs (blue legged variety) in a refugium? <I don't like the idea of putting hermits in a refugium as they are so omnivorous that they might eat anything and everything> My crabs, although great at keeping the sand on the bottom of the tank clean, are becoming pests to my soft corals and I would like to move them into my above tank refugium. <Really? I haven't heard of Blue Legged hermits bugging soft corals>  The refugium is about 10 gallons and has a 4 inch sand bed and contains Chaetomorpha, grape and feather Caulerpa, and probably some other plant life. I got the grab bag of stuff from the LFS. <Sounds good. Do you keep lit 24 hours a day?>
Thirdly, is snail reproduction normal in a healthy tank? <Yes. Pass them around to friends and reef club members.>
Thank you kindly,
Tony Hambley

-Refugium stocked with coral?-
Hello Faq Crew, Hope you are doing well today, <That I am.>
Have a few questions concerning a refugium,
I have a 20 Gallon aquarium and in the process of setting up a 135 Gallon marine tank for fish only to start. <k>
I would like to use the 20 for a refugium, will this suffice? <That would be just fine.>
If so what is the best selection of corals etc. to start off with? <Well, do you want to turn the 20 into a reef or a refugium? I would suggest doing a search through our FAQ's for setting up refugiums.>
can there be fish or should I stick to crustaceans? <Please read up on all the excellent articles at your disposal on this website, along with the plethora of emails asking very similar questions.>
being a shallow tank what sort of lighting should i look at using?
<For a 'fuge I'd suggest at least some PowerCompact lighting, 1 or 2 65w lamps should suffice.>
I am sure there are lots of different ways to go about building one but I am hoping for some good guidelines to follow so i can do it properly the first time as I would hate to make a mistake and kill off the tank and possibly cause Harm to my main display tank. <No worries, it's not nearly that complicated. Read up! -Kevin>
Thanks again
Drew Forbister

Refugium, Mysidopsis bahia 10/14/03
Dear Anthony, Thanks to your guidance, my second refugium continues to thrive.
<to your success/husbandry above all>
Even after re-reading several specific chapters in Reef Invertebrates, I still have a couple more questions: Can Mysidopsis Bahia be mixed with the smaller copepods and amphipods or will the bigger guys just eat the smaller ones. (about 30 gallons, net of sand and rock)
<hmmm... not a matter of predation so much as competition for space/resources... fewer groups will ultimately survive in the end. Best to focus on providing a specific matrix to encourage your target group rather than trying to "go for all" and failing>
I find that these shrimp are bred worldwide and are very available as they are used in environmental testing.
<correct>
I found that the addition of 6 large Mexican Turbo snails has pretty much eliminated all sign of Cyanobacteria. Will these animals affect my "pod" production?
<not much or at all, assuming the copepods find adequate algae to eat (they will)>
I am feeding the refugium crushed freeze dried krill, soaked so that is sinks. Thanks again,
<this will be better for the meat eating amphipods... but not for your vegetarian copepods/rotis. Do consider a phyto drip for the latter unless the macroalgae is sufficiently buck-wild.>
Howard in Wisconsin
<Anthony in his chair>

Adding A Refugium to grow Plankton 11/18/03
Guys,
<and gals... don't forget Marina, Sabrina and Ananda :)>
How do I go about adding a simple ABOVE THE TANK refugium to grow plankton ? Regards Lyndon
<simple enough... take your refugium vessel (small aquarium, Rubbermaid bin, whatever) and drill a  small hole for a bulkhead fitting in it. This refugium is to be fed with water returning from the sump or from a powerhead in the display. Water gets pumped up to it, and overflows through the bulkhead back down into the display aquarium. For pod culture you will want a dense matrix like spun polyester (coarse pond filter pads) or if you light the sump, living Chaetomorpha spaghetti algae. Its that simple. We have extensive coverage on this topic too in our new book Reef Invertebrates by Calfo and Fenner. Anthony>

More about 'Pods - 11/26/03
Crew:
I noticed the question and Paul's reply regarding buying copepods. <Oh yeah!!!> I wanted to put in a good word for Inland Aquatics in Terre Haute, IN. <Yeah, that was my second choice, but having not bought from them before I was unsure of their abilities. Now I know! (and so will everyone)> They sell a wide variety of aquacultured products, including amphipods, copepods, Gammarus and Mysis. <I do like their site and their mission statement>  I have bought his fauna kit before & was very satisfied. <Great!!> It helps to call rather than e-mail if you're desperate for something. <Unfortunately, Gerald doesn't make that very easy with IPSF. His policy is email only in my experience> I called yesterday at 11 AM MST and received 4 bags of excellent algae at 9 AM this morning. <From IPSF??>
BTW, I have found that it is easy to get these creatures to grow in a refugium. I suction-cupped a few of those plastic dish scrubbers to the wall of my refugium as suggested by Anthony. I then added the fauna kit. I soon had hundreds of 'pods & shrimps in the refugium. When I wanted to transfer some 'pods to my new 25" CPR AquaFuge on another tank, I tried to catch some and could not. Instead, I removed one of the pads & shook it in a bowl of saltwater. I was amazed to find at least a couple of hundred 'pods & shrimps in there. Now the AquaFuge is full of them too, This is a great product. I put a 65 watt PC (10K/actinic combo) over it and threw in a wad of IPSF's Tang Heaven Red (red Gracilaria). A month later, I've gotten at least 500% growth. I have tried other means to grow Gracilaria, but this is the first time I have succeeded. <Great information. Similar to how I do it as well. Good on ya, mate. Be chattin ~Paul>
Steve Allen

- Pod 'fuge and a macro 'fuge? -
hi crew; <Hi there>
trying to set up a refugium for my 180 reef and fish tank. Trying to provide food for the fish and the LPS and SPS corals I have. And at the same time, trying to get the side benefits of getting my main display tank rid of some nuisance algae that I encounter from time to time.. My q is this: Do I have to set up 2 different refugiums to do this, or could i just set up one that does both?
<Stocking a single 'fuge with lots of nutrient-reducing macro algae encourages all sorts of pods to take refuge inside. It's the best way to do it.>
In other words does one large enough refugium (was thinking of setting up one about 40-50 gallons) can do both?..
<As above...>
It might seem like a stupid question, but been reading FAQs from your site for 5 days nonstop; and i got the impression that a lot of people DO set up multiple refugiums for different purposes.
<Yes, but in this case, one comes free with the other! This is also not to discourage you from building a second refugium as it would help the tank tremendously. Good luck! -Kevin>
OZZ

Breeding bugs in my refugium
08/06/03
I have a large system,450 gal fowler in house, draining into a 500 gal predator tank and a 300 gal refugium in the garage, they in turn drain to the sump, then back to 450 to complete circuit. I feed both the fowler and predator tanks heavily and the system has been running as set up for 6 months and is working to perfection. No water or algae problems. Refugium has deep sand bed,8 inches, live rock. It's only resident is a small Fimbriated moray that I removed from predator tank and put in the refugium as I was concerned he would be eaten by the 3 foot tessellated moray that lives there.
After about 6 months as set up, I was hoping to see a huge population of bugs in the refugium by now, but even with a flashlight, I only see a few. I am assuming that with the fowler with heavy bioload draining directly into the refugium and the messy little Fimbriated moray, that there should be ample
food to sustain a huge population of bugs. Lots of rubble on bottom. oyster shells etc. along with the live rock. Was thinking of sinking a plastic milk crate stuffed with filter pads in the refugium to see if this home may be more to their liking, plus giving me a way to harvest the little buggers, and maybe asses their population better. Any ideas? Refugium has NO residents
other than the small eel.
Thanks in advance.
<Well, actually, your idea sounds really good. Have you thought about lighting the refugium and adding macroalgae (I'm very partial to Chaetomorpha myself)? I'd say try both, and see what you get. You may also want to try direct feeding the refugium too, something finely ground. Hope that helps, PF>

'Pod Factory - 8/27/03
Dearest Crew Folks:
I am dying to set up a refugium, but I haven't been
able to convince my wife yet (living room 55gal
setup).  
<do consider making it a dramatic focal point with a mangrove seedling and small spotlight on it. Very exotic. Tell her it will turn into a palm tree in 20 years <G>>
Is there a way to have a remote, detached refugium to grow pods and stuff?  
<yes... in fact, it is the best type of refugium IMO - AKA "Upstream Refugium" (use that term in a keyword search of our website from the google tool on the index page wetwebmedia.com)>
If so, how could I make this work?  
<Hmmm... nothing much to it. I will have to dig for the diagrams my brother-in-law did for us for our new Book (have them in AutoCAD... need to find jpegs). Bob and I dedicated about 100 pages of 400 in the new book "Reef Invertebrates" to refugiums, love sand/rock, plants and algae... do check it out if you get the chance:
http://wetwebfotos.com/store/nma-ri.html >
I've searched, but since there are mentions of pods on almost every page, you can imagine how it went.  Can you point me in the right direction?
<indeed... use a more refined search phrase like "upstream refugium"... and a helpful tip: when a long page of text comes up with the hit, copy the entire page to a blank Word doc page, and use the windows search tool to find what you are looking for on it>
Is anyone doing this?  
Yes... for many many years. My first one was just over 10 years ago ;) >
I was thinking DSB, LR, regular fluorescents, yes/no?  
<for heavy pod growth and vegetable filtration... use Chaetomorpha algae and brighter light>
How much should I feed it, a pinch per day of dry food?  What about
harvesting (that sounds like the bigger issue)?  Any help is appreciated.  Rich
<excess pods will overflow nightly. As long as you feed them regularly, provide a dense matrix (the book mentions this at length) and keep the refugium sans predators (no fish or coral)... the brood population will not wane easily. Best of luck! Anthony>

Fish Story? (Tales From The Refugium...)
I have a thriving 18G upstream refugium hooked up to my 80G FOWLR. It's been running for nearly a month with a DSB and a nice big chunk of Kupang Island LR covered with all kind of interesting algae (alas, mostly Caulerpa) including coralline and some other green, red & brown. There is lots of life in there--worms, tiny brittle stars, tiny crustaceans, etc.
<My kind of place!>
I find this tank fascinating in its own right, and spend nearly a much time observing it as I do the main tank.
<I hear ya!>
Tonight, I saw what appears to be a baby fish darting around in there. It is maybe 3/8" long an has the body shape of a Firefish. It darted around the tank very quickly. Coloration is two-toned--creamy on one end and dark on the other. It sure looked like a fish to me. It hides somewhere in the LR. II have no idea how it got there. Any theories as to what it could be? Any suggestions on what I should do to nurture it?
Thanks as always, Steve Allen
<Hmm...Well- I'm not going to insult your intelligence or observation skills by suggesting that it may have been a Mysis or other kind of shrimp...but? Do you think? Maybe...? Possibly? If it was definitely a fish, I suppose that it's possible that a larval fish somehow came in with some of the micro and macrofauna that were contained in the rock or macroalgae (after the fish settled out of the planktonic phase)...I guess the best thing to do at this point is...nothing. Obviously, the little guy is getting his nutrition somewhere in there ( Assuming this is a fish...If this isn't a great example of the value of refugiums as a food source for animals, what is?), so I'd leave him be for a while...keep observing him, attempt to id exactly what he is.. and move him into the main system at some later, more appropriate time. Enjoy this amazing discovery. Try to send us a pic if you can! Regards, Scott F>

Best Algae for a Vegetable Filter/Refugium
Hey Gang, how's it going!  Here's a list of algae available thru "Inland Aquatics" Flora kit, which ones would Anthony utilize I wonder? Dictyota sp. C. brachypus (delicate)* Gracilaria sp.
Halymenia sp. Ochtodes sp., Ulva. Thanks for your time, Scott
<IMO all are excellent except for the Dictyota and Caulerpa (nuisance potential). If you have enough light and water movement, the Gracilaria may be the most utilitarian choice. Some Ochtodes and Halymenia can be very attractive though. Ulva is nice but needs pampered a bit. Chaetomorpha spaghetti algae was not on your list but should be perhaps. It is very hardy and durable... weakly noxious and quite stable. Best regards, Anthony>

New plankton refugium/red algae/ozone
Dear WWM Crew,
This is Howard in Wisconsin again looking forward to the new book and once again trying to learn a bit more of what I don't know about this hobby
<Me too!>
With a two year old set up circulating about 160+ gallons, net - set up and modified 100% in accordance with TCMA and WWM and never a disease process, I should be satisfied. However, several months ago I added a second refugium with "non-Caulerpa" macro algae, peppermint shrimp, worms, copepods, and amphipods.
<Okay>
First refugium has 6 inches of fine sand and is packed with often harvested Caulerpa. Fish bioload is about half the "rule of thumb" level but I know that the large 'convicts' living under the rock and sand in caves have created a space that can't be cleaned and gets little circulation.
<Yes>
Deep sand (5 inches oolitic), inoculations from 3 sources, and fully cured live rock completed the second refugium which I hoped would be the last step in my little ecosystem. I figured  I could grow natural food and perhaps enough other macro algae to later swap out the Caulerpa in the first refugium.
<Sounds good>
Well, the live sand brought with is a plague of red algae which slowly killed off the 4 species of macros and infected everything else in the system. A very productive Turboflotor, lots of carbon, poly filter, 1600 gph circulation, and my "only when needed" 25 micron - 700 gph mechanical filter all proved inadequate.
<Thank goodness>
Frequent chemistry checks continued to show 0 ammonia, nitrate, and silicate (I have R/O and D/I). Nitrates ranged from 0 to 0.4. I used two different low range test kits  to confirm nitrate. I just couldn't figure out what was feeding the red algae!
<... could be a few sources>
Last week, after reading tons of advice from the web and re-reading sections of TCMA I decided to add the only bit of technology in that book that I did not have - an ozone generator and ORP monitor. This is an addition that I know Bob is very high on but I thought I could do without.
<You could>
The ORP monitor read 60, yes SIXTY while chemical tests still showed no chemical pollution. How is that possible?? An ORP test solution standardized at 200 - 250 mv read 205 so I assume the actual reading may have been even less than 60! How is it possible to have so much dissolved organics and/or low oxygen and still be shown that all is well by the chemistry panel?
<It is likely the dissolved organics are at the base of the low ORP>
By the way, my fish and corals have been fine through all this but now that the ozone has produced a steady ORP reading of about 350 the red stuff is fading. I didn't think my water could get any clearer but it has.
<Great>
If your there, Bob, thanks again for the ORP/ozone advice. Now I have it all.
<We'll see...>
I'll be starting over with the new refugium concentrating on Anthony's "non-Caulerpas". I'll wait for the new book and follow you guys' advice on doing so.
<You'll really enjoy the algae section... the book could be labeled "Marine Refugiums and reef invertebrates...">
There is a mass of tiny bubbles on the walls of the tanks which I hope will subside?
<Me too>
I didn't have those with the Turboflotor breathing air only. Are there any creatures or plants that may not like the 350 mv ORP?
<None that you'll likely want to keep>
The Red Sea generator/controller lets me set it anywhere I wish + or - 5 mv, ozone per hour up to 200 mg. (I'm running 150)With a carbon pad on top of the Turboflotor and a bag in the discharge there is no ozone smell at all.
<Shouldn't be. Thanks for writing. Bob Fenner>
Howard

QT and refugium
Hey guys and gals,
<cheers>
I have wrote about my 55 gal corner bow with Aqua C remora skimmer and magnum 350 filter. We are in the process of changing to a DSB and more live rock and also leaving the tank fallow for a month in case something in there killed Piggy the lionfish.  Is there any reason not to move all the sand and rock into the display now and let it cycle there?  
<good heaven's... please don't. Understand that there are practically no exceptions to the 4 week QT rule. We could talk for hours why it is bad to evade the full QT/cycling period. In this case... what is a pest or predator gets into your sand in the display and reproduces? Many many reasons not to cure rock in a display tank>
There aren't any fish and the current live rock in the tank is only 1 piece.  The reason I ask is I have buckets, trash cans and small tanks all over the living room.
<understood... if the display is bare-bottoms, I could concede to using it to sure the rock so that you could screen all matter in search of pests and predators before doing a large water change and adding sand>
Also is there any method for adding a refugium to a glass tank that has no holes in it?  I will eventually need to add one to support the green mandarin we would like to have.  There is no room behind the tank, the Aqua C Remora barely fit.
Thanks for your help Bryan and Dana Flanigan
<actually... there is a common solution and the best type of refugium in my opinion: upstream. Have your refugium above your tank drilled and fed by water pumped from the display below. Such refugia have no problems with plankton shear from pumps since they gravity overflow. If you want to get fancy <G> you can put a single mangrove seedling in it and shine a spotlight on it. Bets regards, Anthony>

Hang on Refugium and inhabitants
Hey guys... I've left you alone for a while, but I'm baaaack...  ;)
<Welcome Jeremy, Don tonight>
Since my tank is not drilled for an overflow, I will be installing a
custom-made hang on the back refugium.  
<Sounds good>
In the interests or reducing the
number of "things" inside the tank I am considering having the refugium
being fed by the return from my Eheim 2217 canister filter (flow rate is
about 260 gal/hour).  I thought I had read in a FAQ somewhere that you
recommend the refugium be fed by raw tank water, but I was thinking that my
setup idea might be better for a few reasons: 1) save money on buying
another pump, 2) reduce the number of artificial items inside the show tank,
3) the water the most likely to be highest in nitrates would be from the
canister filter... the macroalgae in the refugium could tackle this as it's
produced and before it enters the display tank.  What do you think?
<All good reasons to move forward. Forge on!>
Also, what inhabitants would you recommend for this refugium.  It will be
21" X 4" X 16" with a 4-5" DSB.  I plan on having Caulerpa and Hailmeda (sp?),
and was wondering if I need any snails/shrimp/crabs etc to maintain the DSB?
  If so, what species would be best?
<I would stay away from crabs and shrimps and stick with snails. A mix is good, Nassarius, Cerith, Trochus, Astrea, etc. You don't say if this is reef or FOWLR. If reef, I would stay away from Caulerpa and use Chaetomorpha. Have fun, Don>
Thanks in advance,
Jeremy

Refugium predators 3/6/03
Thanks for the reply....HMMMM No macro organisms huh? Such as Sea grass, Gracilaria algae etc???
<no Peter... a misunderstanding. I was responding to your question about putting crabs, snails and the like in... not the algae or plants. By macro-organisms, I meant predaceous animals. Too often folks, put shrimp, crabs, corals, small fishes, etc in the refugium which eat the plankton that you are trying to culture with your "vegetable" matter>
So ...not to combine a fuge for food production and nutrient export?
<food production (plankton) and nutrient export (vegetable filtration) are done ideally and very successfully together here. Just be sure that the animals you add to the 'fuge are merely microalgae grazers to be safe>
Perhaps you are getting at food production upstream and export below...prior to sump as in a raceway scrubber??? Please reply
When is the book ready... Would love to chat more about the breeding/marketing of crabs snails critters and the like
Peter
<excellent, my friend. Best regards, Anthony>

Refugium seeding 3/5/03
Hi Ant... How are you today.
<good, my friend... with hope you are the same>
Was hoping you could help me clarify a few things.
<no worries... I'll just make up something convincing if not <G>>
I am just filling my 90g and 40 g above tank refugium. Live rock going in tomorrow. Now after cycle is done, (4" sand bed in both) I will probably be getting some items from IPSF. Having said that aside from the algae species in the fuge, what should I seed the fuge with for planktonic growth to feed the reef inhabitants.
<I would seek some fellow hobbyists & aquarium societies that can share live sand samples with you to get you mysids, copepods, amphipods, and polychaete worms (Terebellids, errantiates (including bristleworms), etc). Some of this can be obtained from live rock that has not been kept with any/many fishes... more comes from sand in mature tanks and refugiums. Please also check out Morgan Lidster's goods at Inlandaquatics.com  He has cool bugs, sea stars, algae, seagrass, etc. Nice kits like IPSF>
As well, should additional life of identical species also be placed in main tank? or just let it flow down stream?
<the latter>
As well, Do snails and the like (hermits also go in fuge....
Hope to hear from you.
<snails are OK is strictly herbivorous... but no crabs at all (!) or other carnivores like most shrimp. Do keep your refugium very simple and plain (without macroorganisms) if the purpose is to produce plankton>
As well seeing that the market is saturated with those selling and propping frags and the like it seems to make sense to try a possible venture in offering packaged  Fuge kits and the like ...
<yes... very much so!>
of course there is inland and IPSF. Yet was wondering if you could steer me toward info on breeding this sort of life be it micro stars hermits Trochus Nerites Mysis Gammarus etc.
<all worthwhile ventures for certain. And there is plenty of room in the market for all for years to come. Chatting about culturing these creatures will take time. Bob and I wrote almost 100 pages on plants, algae and refugiums in the new book (384pp). At the risk of making a shameless plug <G>... let me suggest you check that out first and follow-up with questions. Heehee... in fact, our last minute additions to the editor for this book in part are what have delayed the delivery by a month as well as added 84 pages to it (no change in price though). Kind regards, Anthony>
 

Heavy Bio-load and Aiptasia scrubbing 3/10/03
Anthony, Thank you for the response.
<always welcome my friend>
I can see your point about using the Aiptasia for only heavily stocked tanks,
<indeed... they are a boon or scourge <G>
At this time I think our tank is packed, and we do feed a lot. One of the reason why I am sure we have such of an out of control infestation.
<agreed... I've done the same thing of course. In fact, it was a corrupt interpretation of the old Adey (Smithsonian) style algal scrubber in a heavily stocked public aquarium that spawned the realization that these anemones could work as animal filters>
We want to change that when the tank is setup again this coming spring.
<agreed... better to not have lemons than have to make lemonade that you don't even like :p >
We had thought about a copperband butterfly but in our area they are never found. I hope that will be a different story in Las Vegas.
<you will find them in time... no worries. All in the US come through LA>
We do have a xenia farm in our tank so it might worth the effort ((if Amy will help out)) to ship it and use that instead.
<yes... awesome!>
Thank you so much for clearing things up. We will look into a better refugium scrubber idea in the next two or three months.
<heehee... when Amy gets her copy of our new book after it is released, borrow it <G>... refugiums, plants and algae take up 20% of the book!>
Clair Jones
<with kind regards, Anthony>

Populating a Refugium
I was wondering if it is ok, or not to use a refugium (10 gal. 2 32w PC lights, as a propagation tank for soft corals such as star polyps and xenia?
<I don't see why not...I've seen people experimenting with xenia in refugiums and raceways as a means of nutrient export...interesting stuff. Besides, when you think about it, if a refugium's purpose is to provide a safe, undisturbed environment for animals to propagate and grow, then why not include some soft corals?>  
Fuge is in an area that it is actually displayed, and I have some big softies. Want to frag them out will this take away from the effectiveness of the refugium? Thanks
<I don't think that this will detract from the effectiveness of the "fuge". Once again, it's all about what you want to accomplish-providing a safe place for coral frags, growing macroalgae, etc. Just plan and execute accordingly. There are few "rules" here, really...Using a refugium is really a "cutting edge" concept...Have fun with it! Good luck! Regards, Scott F>

Refugium? (in a hang-on power filter)
I guess this is more of an observation than a question. I have a 55 gallon
reef tank, DSB and LR. On it I have a Penguin BioWheel 330 filter (with one
wheel removed, actually I could probably remove the other one too). I had
noticed that I had not needed to change the filter cartridges in over 2
months. Normally I would expect overflow at the center of the unit long
before then, indicating clogged cartridges. I decided to change them anyway.
Upon removal, I found that they looked practically unused! I then noticed,
on top of and through the pads, about a gazillion bugs! Talk about a
"biological" filter! Of course, I couldn't throw them out. I guess I will
keep these pads as long as the material stays intact, using the auxiliary
media containers to hold my fresh carbon instead. Is this common?  
<Not common enough, and very fortuitous. Bob Fenner>

Aiptasia in refugium
I have a 65 gallon reef tank with a 20 gallon refugium that gravity feeds the main display tank.  The refugium has become an Aiptasia breeding ground.  Is it possible to add a few peppermint shrimp to the refugium to combat these pests?  Any suggestions are greatly appreciated.  Thank you.
<I have used peppermint shrimp to wipe out Aiptasia. Things I learned in the process: make sure to get Lysmata wurdemanni, the true peppermint shrimp, and not one of the Rhynchocinetes genus, or camel shrimp -- some retailers confuse the two! If you have any particularly large Aiptasia, you should remove them manually, as they may be too large for the peppermint shrimp. You might have more success using a third tank for Aiptasia removal. If the Aiptasia is on live rock or removable clumps of macro algae, I would suggest removing a piece or clump at a time to a dedicated peppermint shrimp tank -- a bare tank with minimal lighting and circulation would be fine. If you add the peppermint shrimp directly to the refugium, they may decide that some of the other refugium inhabitants are tastier than the Aiptasia! --Ananda>

Zooplankton
Hey Gang!  After Anthony suggested zooplankton for my 'Shrooms and Kenyan tree corals, I typed "zooplankton" on the internet, and this site is one I checked out. http://www.rotifer.com/  Interesting stuff. Does a refugium produce these kinds of life? Just curious, Thanks for the time! Your friend in Scott.
<cheers, Scott.. yes- refugiums produce far more diverse and nutritive forms of plankton (photo- and zoo-). We have an extensive chapter on refugiums in our new book (Reef Invertebrates) ;) Do consider installing a fishless refugium... they are tremendously helpful additions to most any aquarium. Anthony>

New fauna refugium, Iron supplement?
Dear Crew, Avoiding Caulerpa in this box designed to breed small crustaceans,
<a good start already... seriously>
I have put in Codium, red grape, Ochtodes, Ulva, Chaetomorpha, and "tang heaven red". (can't find Sargasso or 'seagrass' suggested by Steven.)
<no worries on the Sargassum weed for smaller vessels... too fast growing>
I read elsewhere that a chelated iron supplement will help these slow growing algae and not harm the reef.
<agreed... within reason>
I add nothing without advice from WWM. Will the iron effect the rest of my reef system?
<it can benefit or harm the system like most anything else... Iodine, Calcium, etc. A good rule of thumb is that you should only dose what you can test for. If you are willing to test and monitor iron levels, then great. No targeted level necessarily (within mfg recommended range)... just prevent it from straying from untested and blind dosing. For all else, small frequent water changes will serve you as well or better (weekly recommended). With all that macro/plant matter... please be sure to always use carbon and change it often (1 oz weekly per 30-50 gallon rather than 4 oz monthly, for example). This is necessary to maintain water clarity from all of the discolorants released>
I can temporarily stop or slow the flow through this refugium or I can perhaps stop the iron at the overflow with a chemical filter. (PolyFilter or a small bag of carbon).
<no worries.. the iron can benefit coralline algae and others in the tank proper. Just don't overdose>
Perhaps you can help me identify a milky white "slime" that covers part of the sand bed (oolitic plus several live sand inoculations) when touched it comes apart like  a wet piece of tissue paper??
<strange... not sure without more to go on>
How do you feel about small hermits and/or snails in this refugium?
<snails will be fine or helpful, hermits and crabs of all kinds will almost certainly be a detriment>
Any other plankton producers that will not eat the macro algae or the "pods"? What are the "sea bunnies" offered by Indo Pacific? Would they be worthwhile?
<a snail/gastropod. Interesting but not necessary>
Thanks to Bob for suggesting this addition to my system. Howard in Wisconsin
<Anthony in Pittsburgh. Home of the awesome Pittsburgh Steelers :) Good luck to the WI folks and home team for Favre winning MVP of the year... I'm voting for him!>

Getting Rid of a Refugium
Hi WWM Crew,
I have a 30 gallon refugium hooked up to a 150 gallon reef tank + 30 gallon sump. I have quiet a few corals and 9 passive reef fish except the sailfin tang that I will have to return back to my LFS sometime end of this week (for obviously a wrong choice on my part). I would like to add fish or an exotic colored invert to my refugium as it looks too dull with Caulerpa only.
<Please understand that as soon as you add a fish to your refugium, it is no longer a refugium. A refugium is a place of refuge for tiny creatures where they can live and breed free from predation. Any fish you add will consume some of these beneficial animals and turn your refugium into just another inline tank.>
Is this something that has been tried or even suggested?
<Not really because it negates the purpose of building a refugium in the first place.>
What would be a good choice so that it does not eat up all that the refugium is supposed to produce for corals, etc.?
<Leaving it empty.>
Was looking forward for fish like clown pair or other small fish that lives in pairs and is interesting to watch. Smaller the better. I have also heard others suggesting a small cucumber and a couple of snails in a refugium. Is this true and should do that?
<Some snails maybe beneficial.>
Right now I have Caulerpa, miracle mud and aragonite substrate. Sand bed is about 3 inches. Your help is much appreciated as always. Here is a list of my fish: 1 sailfin tang (will be returned), 1 green Chromis, 1 false percula clown, 1 pyramid butterfly, 2 yellow Coris wrasse, 1 orange spotted fairy wrasse, 1 purple firefish, 1 fathead Anthias, 1 blue/yellow tail damsel. Regards, Razi Burney
<Best of luck to you. -Steven Pro>

Refugium Flora and Hair Algae Woes
Hello Everyone !
<Good morning! Scott F. here today!>
Have a general set-up question regarding my 50 gallon refugium. I have a 300 gal mixed coral reef tank (mostly SPS).  The reason I added the refugium IS NOT for nutrient export but for zooplankton, copepod, Mysis production for feed into the main tank.
<A GREAT application for a refugium!>
Given this, what would be a good setup for the refugium as far as the flora is concerned? Right now I have grape Caulerpa and feather Caulerpa, which I am slowly removing to make room for other macroalgae species that are less toxic/problematic.
<A great move!>
I am thinking of replacing the Caulerpa with Ulva fasciata, Chaetomorpha, and Thalassia from Inland Aquatics. Does this make sense, given that my refugium's purpose is to produce live food rather than nutrient export ?
<Great question. Yes, it does. Even though the macroalgae that you mentioned are generally slower-growing than Caulerpa, they perform some other functions that are exactly what you're looking for. Chaetomorpha, for example, is basically a Mysis/zooplankton "Disneyland". Since I switched to
Chaetomorpha, I have noticed an explosion in the Mysis population. This algae seems to provide an ideal home for them to breed and feed amongst. Ulva is also an excellent substrate for amphipod growth. Thalassia is a very slow growing plant, probably not a great choice for nutrient export, but once again supports plankton/diatom growth. Keep in mind that you need a deep sand bed for this species to root in (approaching 5-6 inches) or it will not do well. You should definitely get a copy of Anthony's "Book of Coral Propagation" for lots of interesting details on refugiums and macroalgae use. You'll love it!>
Also, I have been battling the "Hair Algae Beast" in my main tank.  I have traced the problem as being caused by the following:
1.  Protein skimmer hose (long) was plumbed into my home's water/sewer drain pipe and was clogging, yielding inefficient skimming....now I use a collection cup w/>short hose and I clean the hose while cleaning the collection cup
<Good move. A clean skimmer is essential for proper function and waste removal. Try to clean it a couple of times a week, if you can.>
2.  Lights were too old and lost color temperature...replaced and right away my anemones, clams, etc opened wider...an indication of proper wavelength.
<yep!>
3. Insufficient water changes...Now doing automatic daily 6 gallon changes
<Wow! My kind of reefer! I'm impressed!>
4. Coral die off due to high temperatures when on vacation....replaced Teclima Chiller (many problems, 3 replacements from Fritz, finally obtained refund... I do not recommend these chillers) with Aqualogic....much more reliable....0 problems so far (6 months)...
<Glad you resolved that problem>
I also replaced some of the coral which should help CO2 uptake to some extent.
<ok>
5.  Excess CO2 from calcium reactor....temporarily disabled reactor until hair algae is gone.. I have a K2R and I can't seem to get the alk / calcium that I need without using excess calcium.  Therefore I bought a second chamber and also I now run an AquaMedic Kalkreactor for makeup water.
<Quick thinking on the CO2 problem!>
6. Excess feeding.... I cut feedings in half until algae is gone
<As you know, feeding is okay, just don't overfeed! Your increased lighting from newer bulbs should make up for the lesser feeding of your corals>
Now that I have traced the problem down and made the above adjustments/changes, the hair algae is not growing back.  But the old stuff is still there....
<Tenacious stuff, huh?>
Do you have any suggestions  to get rid of existing algae? I just want to rid my tank of it  once...after it is gone I think the above implemented changes will prevent re-growth. Is there anything I can in addition to daily physical extraction, vacuuming, activated carbon/poly filter to get rid of the existing hair algae ?
Chuck Spyropulos
(banned from reef-central by heavy-metal spineless guy, Ron Shimek) hee hee hee !!!!)
<Well, Chuck, your corrections in husbandry and responses to the problems you've encountered so far have been great, and I hope that our WWM readers  can learn from your methods! Apart from employing purposeful consumers of excess algae (i.e.; tangs, Centropyge, some blennies, etc.), I think that just yanking out the stuff is the best way to go for now. If you have extensive coral population, I'd be afraid to throw in a fish that could start munching on your precious corals. Manual extraction is a pain in the rear, but I think it may be the safest way to go at this point. And- you always are free to speak your mind here on wetwebmedia! I was gonna make a joke about the food/metal connection put forth by a certain "authority", but thought the better of it! Take care!>

Xenia in sump
Hello whoever,
<right back 'atcha unknown question asker>
I've got a question about putting xenia in my ecosystem sump.
<OK>
Would it hurt the xenia to have the 24/7 lighting?
<yep>
I'm probably going to give the rock full of xenia away within the next week so it wouldn't be in there for an extended period of time.
<alas... unlike the rarity Caulerpa, Xenia and most photosynthetic creatures cannot remain in stasis under 24/7 illumination. They will suffer and must be allowed to conduct respiration. It is truly your goal to export this creature alive from your tank, you must allow a day night period for the coral to prevent a potentially fatal luminary shock in time. Besides... the 24/7 lighting method is marginally beneficial at most. It has been dispelled as a preventative for vegetative events in Caulerpa. Caulerpa is prevented from going sexual by regular pruning within the known 3-6 month life cycles of more than 40 recognized species>
I just don't want the xenia to spread anymore in my tank! Would this work?
<My advice is to run a regular photoperiod for the next week for the Xenia and then return to 24/7 lighting if you like after its gone. Best regards>

Refugium Startup
Hi, another question that I hope is worthy of your answers.
<Hope that my answer is worthy of your question! Scott F. with you tonight>
I have read (just recently) on your frequently asked Q and A's that one or all of  y'all suggest an upstream refugium that will produce 'pods that will feed the system and the corals?  Is this possible and what exactly would be put in the refugium that would be able to produce quantities that would be able to feed my fishes and my corals?
<Certainly is possible. You could use various grades of substrate (Course substrates tend to produce amphipods, medium to fine substrates encourage smaller species, like copepods, floating forms of macroalgae, like Chaetomorpha, provide refuge for Mysis populations) to encourage the growths of different creatures.>
I have a 180 gallon acrylic with a 60 gallon acrylic aquarium as a sump, with numerous corals and fish.  My tangs are voracious eaters of frozen Mysis shrimp and also greens when possible.  I also have several other fishes that would join in the smorgasbord.  I have been thinking about a 24" hang on refugium by CPR and need to know what would be a possibility as far as stocking the refugium with live critters that would produce enough to keep my inhabitants happy or content.  Any ideas or insight?
<The refugium that you are considering could certainly produce enough life to supplement your feeding, but not enough to rely on it. Do read some of the many FAQs on refugiums that can be found on the wetwebmedia.com site, by using our Google search feature>
Where would I get live starter critters that would reproduce in the refugium? Thanks as always, Jeff
<Some can naturally be found in live sand and live rock, or macroalgae. You can also find a willing fellow hobbyist with a thriving refugium who could offer you a "starter culture" of such animals. And, of course, you can check out etailers, such as Indo Pacific Sea Farms and Inland Aquatics, which sell these creatures. Study, plan, and execute! And most of all, have fun doing it! Good luck!>

Jaubert Method Refugium
Hello again! As always thanks for your prompt responses and considerable patience with what probably seems like an endless supply of repetitive questions. Anyway, I have decided to construct a refugium (after researching www.WetWebMedia.com) using the plenum method and a 4 inch sand bed.
<Ok>
I will alternate light with my main tank and will not keep any burrowing fish in the refugium.
<You should not keep any fish in the refugium.>
What would you recommend as a good flora/fauna starter kit and what type of inverts should I avoid placing in the refugium?
<I would obtain some live sand, a few really good pieces of live rock, and a detritivore kit or two. The idea is to seed the refugium with a broad diversity of critters and using multiple sources and media accomplishes this well.>
Also, I was thinking of using Natures Ocean live aragonite (.5-1.7 mm) diameter for the entire 4-5 inches and just adding maybe 1 inch of the same per year as it dissolves.
<I would save your money and buy dead sand. If you want to buy some live sand, obtain this from your LFS or online retailer, not from a bag that is sitting on a shelf for who knows how long.>
Mr. Fenner has suggested using a two layer method with inert screen in between. Is this simply to prevent burrowing animals from getting to the lower layers.
<This is a description of the Jaubert method and I would have to defer to his writings, Dr. Jean Jaubert. You should be able to find his actual writings with a quick search.>
I understand that different microorganisms prefer different grain size so if I stick with one type (see above) will I be able to sustain a well rounded population of microorganisms?
<The fine grain sands seem to be the best.>
Thanks again!
<You are welcome. -Steven Pro>

Refugium and "Hitchhikers"
Dear Crew,
<Steven Pro in this evening.>
Sending to both addresses because it seems as if you are still having the occasional email twitch...
<We don't get any messages addressed just to the WWM email, but if people CC them to both the WWM address the hotmail account, we get two copies. Very strange. Glad I just have to worry about pet fishies and only have to know how to type on the computer.>
My apologies if I missed the answer to this in the refugium FAQs, and please feel free to just shoot me a link if I did......
<No problem.>
First of all MANY, MANY thanks to Steven Pro in his assistance and suggestions in setting up my refugium.
<Glad to have been helpful.>
I ended up using a 20g long and getting my local glass cutting place to cut me a divider out of double-thick glass, which I then siliconed in place to divide the 'fuge into the pump area and the rock/sand/algae area. I think it's way cool.
<Me too!>
I have one small thing to run by you guys: The water goes from my overflow box (undrilled, sorry Anthony), through a plastic hose, down to the refugium in the cabinet under my 55g main display (couldn't do it above as suggested in Anthony's book). The water flow into the refugium is fairly strong. There is 15 lbs of Carib sea "reef sand" grade sand and about 20 lbs of LR in there along with assorted macro algae. The water flow is heavy enough to "move" the sand, so there is a little round patch of bare-bottom aquarium visible. Is this too heavy or am I twitching unnecessarily?
<See if you cannot add a T or elbow to the end of the drain hose to direct the surge from going straight down and disturbing the sand.>
I wish I could tell you what kind of pump I have, but I got it from a store going out of business (before I knew ANYTHING) and didn't pay attention to what kind it is, and it has no brand name or model listed anywhere.
<Kind of weird it is not labeled in some manor.>
Second question has to do with critters I saw in the system. They are either rock hitchhikers or they came in on all the algae and Thalassia (sp) I got from Inland Aquatics.
<Be sure to tell us how the Turtle Grass settles in and grows. Jason, Zo, and I all would like to get some for ourselves. Getting undamaged fronds can be difficult.>
They are snail-like (if not in fact snails), no shells though, the exact color green of grape Caulerpa, about half an inch in length. I have only seen them at night when the lights are on, and they are usually crawling on either the Caulerpa or the rock and it looks like they eat algae, from what I can tell. I went looking for pictures on the site, but didn't find "them". They are roughly the same shape as the photo of the Roboastra arika listed in the Nudibranch section. Need a pic?
<A picture would help, but see if you cannot get a copy of Baensch Marine Atlas Volume II. There are several likely candidates in there.>
Harmless or something I should remove?
<More than likely harmless, enjoy.>
Many thanks as always, Rebecca
<Have a nice night. -Steven Pro>

Second Refugium
Dear Bob and friends,
As you suggested, I have begun work on a second refugium for food production. It will be about 40 gallons in size with 7 or 8 inches of fine sand (mud?) and about 30 pounds of well seasoned liverock. I have several decisions to make regarding stocking. I want this to be an interesting highly diverse tank whose main purpose is to provide larva, egg strands, copepods, etc. as food for the fish and inverts in the show tank. What is the very best substrate for this purpose? Oolitic?
<I would use fine sand.>
In addition to copepod and pink bristle worms I am considering the following creatures. Please comment. Sea Biscuits, cucumbers, sand dollars, peppermint shrimp, pistol shrimp, volcanic shrimp, Mysis shrimp, and several varieties of snails?
<Snails and Mysis sound ok>
I want creatures that multiply, eat detritus, and produce food, nothing that eats the copepods and amphipods. I have read that starfish clean out the sand bed and shouldn't be in the refugium. Is this true for all starfish? Howard
<The miniature serpent starfish would be ok. -Steven Pro>

Refugium
Bob & Crew,
On page 76 of your book, can you id the plants in the refugium?
<In CMA, yes... likely a Rhizophora mangle (Red Mangrove) towering above all (see: http://www.wetwebmedia.com/marvascplts.htm), and a mix of Penicillus, Halimeda et al. tropical West Atlantic macro-algae species submersed (http://www.wetwebmedia.com/maralgae.htm and beyond)
Bob Fenner> 
Thanks
Mark

Question on live food
Hello again. How are you?
<Fine thank you.>
I have set up a tank to grow amphipods (Gammarus type) to replenish the amphipod population in my 29 gallon display tank. My amphipod population in the display tank has basically become extinct due to my scooter blenny and white striped cleaner shrimp. The amphipod tank is an isolated 10 gallon tank, (so I guess it's not a true refugium, or at least not an elaborate one). I have a heater and sponge filter in
there. My question is, are there any precautions I should take before adding the amphipods from their tank to the display tank?
<Adjustments for pH, temperature, and salinity.>
When I get a good population going. I don't want to introduce any diseases into the display tank from the amphipod tank.
<Very little chance/no carriers>
Thanks again, Kevin
<You are welcome. -Steven Pro>

My second (fauna) Refugium
Dear Bob and friends,
I just passed my second anniversary as a reef keeper and am working on the final(?) piece to this 150 gallon almost automated system. My first refugium, a 30 gallon box, with 6 inches of crushed aragonite, live rock, and a thick bed of (regularly harvested) Caulerpa prolifica has helped give me perfect chemistry and dissolved oxygen as well as food for the tang. Still never a disease process of any kind. You have given me advice regarding the second (plankton producing) refugium which is now ready to fill with 5 - 6 inches of "mud", a variety of fauna, and enough flora to keep the fauna happy. It is a 40 gallon box with power compact lighting fed by part of the overflow of the show tank (adjustable). It has a temporary 'Skilter' and heater which I will run until it is all settled and I open the valves connecting it to the total system. The overflow to the main filter sump is screened with a large drilled acrylic screen so nothing over 1/8 inch can pass. I have read everything I can find on WWM and elsewhere (including Thiel, Shimek, and Leng Sy) about refugiums and mud. There is much disagreement on what mix of fauna can/should be used and what kind of mud/substrate to use.
<Yes. I can only tell you what has worked well for me.>
I have gone through the research and the suppliers and am very confused. At the risk of a too long an email may I present some of my findings and ask for your opinion?
<Sure>
My system is based entirely on your book, WWM FAQs, WWM articles and your advice.
Available substrates: Live Florida Sand from etropicals.com? Fiji live sand from Flying Fish? GARF Grunge? Indo Pacific 'Wondermud'? Inland Aquatics live sand? Florida Keys live sand from Saltwater Fish.com? Carib Sea Oolitic from Reef Fanatic? Miracle Mud from Eco Systems? Money no object, which would you choose?
<Right now, I would start with dry sand and seed from several different sources live sand products and/or detritivore kits.>
A mix?
<Sure>
Fauna selection is even more confusion. The obvious is to not introduce one plankton producer that eats the others and to use sand stirrers but no sand sifters. Inoculation with copepods and amphipods is a given but to add diversity and plankton sources and to consume detritus (and make it all interesting) there are other options:
Gammarus and Mysis shrimp?
<I like Mysis.>
Small blue leg hermits? mussel rocks? Volcanic shrimp? Small brittle stars?
<The tiny brittle stars are good too.>
Common sea cucumbers? Peppermint shrimp (for their egg strands)? Urchins? Various snails?
<I am a big fan of using various species of snails vs. any crabs.>
Nudibranch? Spaghetti worms?
<Spaghetti worms are a stable of most live sands or sand products.>
"Sea Bunnies"? Other suggestions from the WWM crew?
<I would even add small bristle worms.>
I will use no Caulerpa in this box. Ulva? Tang Heaven red? Mangroves? Other plants? Leng Sy's Caulerpa sertularoides that does not proliferate?
<I would lean towards a Sargassum, sea grass, or Chaetomorpha.>
I know this email is extensive and thank you for your patience. Really, Bob this hobby and WWM have been a joy and have made me a much more observant, knowledgeable diver as well! Now there is even more beauty in the details, in the smallest things on the reef. Howard
<I agree. Some of the most interesting creatures are the tiny ones. -Steven Pro>

Refugium Performance
<Robert... Anthony Calfo in your service while Bob is away>
My 90 gal. net reef show tank holds a variety of hard and soft corals, mushrooms, polyps, and fish. I continue to try to find ways to make this a complete Eco-system that will not need much in the way of added food.
A 20 gallon refugium loaded with Caulerpa racemosa, and a deep sand bed is fed with 200 gph of effluent direct from the show tank then into the out-put chamber of the main sump thence back to the show tank. From the in-put chamber a separate 400 gph is treated with carbon, mechanical filtration, u/v, and skimming. I add Mg, St, and I on a regular, monitored basis. All water parameters, temperature and salinity are constant at ideal numbers. There has been no disease since this system started up 14 months ago.  By placing a filter bag over the effluent of the refugium I find 2 to 5 copepods of various sizes collected over a 24 hour period. A similar number are found when I filter the water coming down from the show tank. How can I improve the system to develop a steady supply of "plankton" for the corals and live food eaters such as cardinal fish?
<fishless, mature refugia in time... explore grades of sand for targeting specific plankton in culture>
What cultures or creatures can I add to the refugium? 
<absolutely no fish... the rest will depend on the form and function of the refugium style to establish>
I have no noticeable micro algae. Should I try to grow some in a small lighted box in the main sump?
<not necessary but can be fun or useful if done right>
With your advice, I use no bottled liquid foods or "formulas". 
<excellent... otherwise, pollution in a bottle>
I do the Fenner fresh mash" but would like to replace this with natural plankton generated in the refugium.
<ideal if you succeed>
Once or twice a week I put in a batch of freshly hatched brine shrimp (yokes in tact). The fish love them but are these useful, adequate food for the corals and mushrooms?
<only if very fresh from hatching and better by far if fed and soaked in Selcon additive (keep refrigerated)>
Howard
<if interested in further unique system components such as refugium styles, plankton reactors, multi-gradient systems, etc... I have written about them at length in my new Book of Coral Propagation www.readingtrees.com with kind regards, Anthony>

Copepods and UV Sterilizers
Hi,
Will running a UV sterilizer kill beneficial copepods and amphipods?
<If it is powerful enough, the flow rate through it long (time-wise) enough, yes>
I had a large bug explosion a few months ago so I got a dragonet and he was eating like crazy. Now, he still looks like he's constantly picking through the rock and sand, but he is getting skinny as if he can't find enough to eat. I'm thinking about setting up a refugium under the tank and getting a amphipod breeding mat and starter culture from Indo-Pacific, but want to find out why the visible bugs are gone? (Still see larger bugs from time to time.)
<Likely consumed by the Mandarin/Dragonet... they can/really mow through such fauna. I do agree, urge you to go ahead with your added sump/refugium plans. Many benefits, much fun. Bob Fenner>
Thanks for your time,
Michael

Breeding Fish & Inverts in the Refugium?
Hello Almost Knowing One,
<You reached Steven Pro today. Anthony Calfo and I are helping out for the time being.>
I have read through most of the FAQ's but to no avail. I am looking for information or ideas for a guppy or molly type fish that I can breed in my refugium for my saltwater tank. I had a Sailfin molly pair but they are too big for my small refugium (10 gal). They did well indeed and bred a couple of times before the female got sucked into the power head.
<The Mollies are your best bet, but they will eat your other planktonic life forms in your refugium. You might want to leave them out and get yourself some creatures specifically for a refugium, like Mysis shrimp.>
The refugium will also hold a few peppermint shrimp some live rock and plenty of macroalgae. What kind of fish should I buy and do you have any tips on keeping the alive in such a high salinity.
<Very slow acclimation over several days.>
The refugium is hooked up to a 46 gallon fish/reef tank.
<Leave out the big animals and watch with amazement the proliferation of tiny bugs.>
Thanks for the support in this expensive and expansive hobby.
P.S: Your site is great.  -Chad S., Springfield, MO
<You are welcome. -Steven Pro>

Refugium question
<<Greetings, JasonC here doing a cameo while visiting with Bob in sunny San Diego.>>
I have read most of what was on the site about refugiums, and am still not sure of what if any "critters" to add to the refugium. I will have a small refugium in the sump under my tank with a 3 to 4 inch layer of live sand, some LR, and Caulerpa. Do I need to stir the sand or add critters to do this? <<I wouldn't think so. The live rock will add [over time] plenty of 'stuff' to the sand bed and refugium. You could add some stuff to give it a kick start, but it's really not a requirement.>> If so, what kind. <<There are a couple of detritivores and live sand starter kits which are available from the various online e-tailers.>> Also, what kind of maintenance in the way of vacuuming, etc., should I do in the refugium? <<none, except removal of excess Caulerpa from time to time - this is important by the by as it is the prime means of nutrient export from a running refugium. Cheers, J -- >>

Sump Stocking
Hey guys, just got a custom sump for my FOWLR tank. Tank has high a higher
than average bio-load as it has some carnivores in it. Its a 125Gal with
same amount of LR, < 1/2in substrate, with a 30gal sump. Anyhow, nothing is
in the sump right now. Read through most of the FAQ's, anyhow kind of torn.
Should I put a ton of little pieces of live rock ? 
<could be a dangerous detritus trap with heavy feeding>
or a deep sand bed with some rock or mud ? 
<if you expect nitrate challenges...possibly>
What would be the best benefit in this type of set-up ?
<denitrification>
The size of the sump is 30x13, so it isn't terribly large. . . Thanks
Ed
<do consider an empty sump with a baffle (low glass divider) and treat the sump like a settling chamber to collect sediment for near weekly removal assuming the skimmer doesn't work perfectly every day <wink>. Anthony>

Re: 10 gallon refugium
Bob,
How about buying some mangroves and sticking them in my sump. Will this
method be just as efficient as adding a refugium? If so how many mangroves
will I need for my 240 FO tank?
<This sump is too small for such additions. Too much likelihood of the tank breaking. Bob Fenner>

About refugiums:
In my refugiums, things look great. Now I want some macro algae and 'pods. What
is your best recommendation for seeding both of these organisms.
<Time going by... with decent quality live rock, most always enough of these sorts of organisms will be there, grow on their own. If you're anxious, want to speed things along, you can buy starter cultures from outfits like Inland Aquatics to seed, overwhelm all>
I do not have
miracle mud. . . . My LFS will sell a complete Caulerpa strand for like 40
bucks, but I don't think this is worth it. Is it? 
<Sounds pricey. You only need a few inches...>
I also plan on going with
a reverse light cycle (It has been just too difficult to keep the tank's temp
under control with the refugium light on 24 hrs per day. Also, do you use
carbon in your mechanical filter?
<Please read here: http://wetwebmedia.com/chemFiltrMar.htm>
Right now I am using just a regular blue (I
don't know the material) filter with a piece of what feels like really tough
paper towel (which came with the tank from Tri Tan) and I replace it about
every other week. Is this OK??
<Is this "doing what you want"? If so, okay>
Thanks again, in advance
Rich
<Be chatting. Bob Fenner>

Re: Refugium, Deep Sand Bed, and Diving.
Whoa fast, fast response. Thanks for your help! I have a follow up
regarding my refugium. Is it possible to raise cleaner shrimps in a
dedicated refugium?
<Yes>
I wish I had more that a week in Grand Cayman. I have seen all kinds of
wonderful pictures of reefs there. I don't think a week is enough either.
I know I am going to work in "Sting Ray City" experience. 
<A "standard">
The dive agency
that we are using is Ocean Frontiers. I have bought a camera and hope you
use lots of film! I do have a trip planned for Fiji in June '02 I assume
there are great dives sites in Fiji also.
<Yes... am off to Taveuni 11/27... Supposedly heading back in May... Maybe we'll meet up there in June!>
As always, warmest regards
Brad
<Be chatting. Bob Fenner>

Concerned about refugium repair
Hi Mr. Fenner,
2 questions. First what is your opinion on this. I placed on Friday, Dec. 28, a piece of live rock with a bunch of 3 types of button polyps, yellow, and orange sponges underneath, and a section about 4" sq. of an encrusting type of coral that looks like a Favia fagrum from picture on your website in my tank, and it is about a foot to 15" upstream from my nice toadstool. Since Saturday my toadstool has not been opening up. It is still standing nice, and tall, and full. Everything looks great except it hasn't opened. I've read that buttons cannot be put near leather corals, but even at this distance it still matters?
<Yes... chemically>
Mind you the toadstool was put in the tank only 2 weeks prior, so is it maybe just finally acclimating to my tank, and the timing is just a coincidence, or would you go with a warfare going on between it, and the polyps? 
<Some period of adjustment, detente at least>
I have since rearranged the flow in the opposite direction, and now the toadstool is upstream from the polyps. Would this make a difference, (how much time should I wait to see if it helps?) <Days, a couple of weeks> or maybe I should move one, or the other further away( I do have the space, my tank is 5' long).
<I wouldn't keep moving them>
Second, I want to repair my refugium, which is built from a store bought glass tank. It has Miracle Mud, Caulerpa, and LR in it, and lit 24/7. The problem is when I built it I used acrylic that was too thin for the separations, and now the water flow has made them bend, and the silicone is starting to let go on them. I would like to redo the separations with thicker pieces, and silicone it better. The refugium could be shut-off from the main sump system (bypasses it through a tee with shutoff valves) with no problem to empty out. My concern, and worry is will this do any damage to all the critters, Caulerpa, and the mud bed which is pretty live if I take every thing out for about 2 days ( the time to fix, and let the silicone dry)?
<Mmm, you need to make provision (another going system) to keep all the live parts live...>
My sump would still be running, and circulating the water in the main tank, and I do have a Red Sea Berlin XL skimmer running from the sump, so there will still be oxygen, and filtration from the skimmer happening. Main concern would be the water parameters, and would they change suddenly?
<Hopefully not>
I have fish, and corals in the tank. The main tank is 120 G. with a 50G. sump ( not including the refugium which is separate). So there is a decent total volume of water to not let it change that quickly. 
<Agreed. You should be fine>
If I put the mud, and Caulerpa in a tub with a powerhead to circulate, and aerate, would this be safe for the life in there?
<Plus a heater, and if you can something in the way of a mechanical filter... like a "cycled" canister or hang on power type>
Is this a bad idea to disconnect it from the main system for a couple of days?
Concerned, and worried about how to fix it!!
Greg N.
<Needs to be disconnected to fix. Or another sump made to swap out in real time. Bob Fenner>

Refugium Questions - Copepods and such
Good evening Bob,
<Good eve to you>
I emailed you a few days ago about suggestions for a refugium and the future of my current wet/dry system. I have began setup of the Aquafuge 18 refugium and had a few follow-up questions to aid in my 3, 6, 9, and 12 month goals and direction.
<Okay>
After the refugium has established itself and I convert my wet/dry area into another mini refugium, should I tie the two units together or leave them independent of each other.
<I would tie them together>
There is no risk of overflow in either circumstance. The existing wet/dry system uses a powerhead to return water to the tank, the Aquafuge uses a powerhead to pull water from the tank. The main advantage I see is one less thing to plug in. The only downside would be any micro-organisms in the wet/dry area will have a heck of a ride getting to the refugium. Then again, they will be taking that ride to the tank anyhow.
Am I overlooking anything?
<Perhaps... I would "tee off" the inflow to both, with only a bit of flow to the refugium sump and have it in turn flow (parallel, not in series) with the main sump>
My other question is regarding copepods and other similar critters. I am really excited about the possibility of having
these guys thrive in my system, I am just unsure how they get there. There are a few places around on the net that sell
"Starter kits" and such, but are these needed?
<Not generally... seems almost like magic, but many creatures come in by way of live rock, substrates, other organisms... make their way to the less-predatory areas...>
Wouldn't a few of these guys piggy back in on live rock, live sand, fish, etc? If so, wouldn't it only take a few months before they would be thriving in my refugium and feeding guys in my main display?
<Ah, yes>
Thanks yet again for your time and knowledge.
Benji
<Thank you my friend. Bob Fenner>

Resource partitioning
I've been considering on adding a refugium and most likely in the Leng Sy Ecosystem style. That is a sump with the Miracle mud and a bed of Caulerpa being lighted around the clock. Now I was talking with a friend of mine and he was suggesting that the Caulerpa in the eco-sump and the bacteria in the plenum (which I have in my system right now) will compete with each other for nitrogen. With only 1 that will win out and I he thinks that it will be the Caulerpa. As a result the plenum which acts as a nutrient sink will cause the Caulerpa to grow like crazy due to the excessive nutrients that will be released when the plenum system shuts down. Sounds pretty interesting to me but I don't think that such a thing will happen though. I feel that with a heavy bioload of fish along with corals and feeding there would be enough food for all the bacteria to go around. Bob I am interested in creating the ecosystem for the good benefits attributed to it including the plankton heaven which some of it makes it into the main display for all the corals and the fish to utilize. Your thoughtful comments would be greatly appreciated.
Louis & Ivonne
Please use our permanent address:
>>
Interesting thought processes evident here... Do agree that some sort of net transfer of energy, bioaccumulation and nitrogen-sinking will occur in the refugium/mud filter in competition with the anaerobes in the plenum... but do agree with you, this should pose little problems really... If your free nitrogen as nitrate dips below where you want it through testing or bioassay (let's say you want 2-5 ppm...) then you can always "harvest" part of the Caulerpa... I would go ahead with your plans.
Bob Fenner

Refugium
Hello Mr. Fenner (AKA God of Reefs)
<Yikes, am just a pet-fish kind of guy, please>
I have started a refugium and the Macro algae is doing good thanks to you. I am seeing a lot of algae build up on the acrylic of the refugium, (I run my lights opposite of the main tank approximately 13-14 hrs.). I was wondering, if it is ok to put some snails in there to clear up the area I can't see through?
<Should be fine>
Also is it ok to put a few Neon gobies in the refugium (hoping they will breed) since every time I place them in the main tank they end up getting sucked through the overflow and never make it.
<I probably wouldn't... as they'll likely eat most all the beneficial zooplankters there... instead, put viable screens (like a pin-type bio-ball) on/over the overflow edge, or other strainer to keep them out>
Thank you, Rob
<Be chatting, Bob Fenner>

Survival of microscopic organisms in refugia
Hi Bob,
I want to thank you for answering all of my previous questions concerning
refugia - I have one more. In preparation for setting-up a 180 gallon
marine fish-only tank, I am researching the Ecosystem filter developed by
Leng Sy (It seems that Mike Paletta, among others, have given it good
reviews).
<This is a very nice unit... and the technology is sound>
One aspect of interest to me is that the mud refugium likely
provides a home for microscopic organisms, which can be transported to the
main tank via the return pump connected to the refugium. I thought I read
in the refugium section of WetWebMedia that we shouldn't worry too much
about microscopic organisms being shredded by the impeller of a return pump.
This was good news to me, as I like the idea of placing the refugium below
the main tank, which is also the suggested configuration for the Ecosystem
filter designed for larger tanks. However, the idea that impeller pumps do
not significantly shred microorganisms seems to be contrary to the position
held by others, who place the refugium above the main tank so that
microorganisms may drain from the refugium into the main tank without having
to pass through a pump impeller.
<There is currently quite a bit of discussion on the various hobbyist listservs over this very issue... Having operated such gear for many years and being semi-observant and interested, I'll assure you that enough, a bunch does "get by" the small centrifugal pumps used in our interest.>
Are you aware of any studies that have tested the question of whether
impeller pumps shred microorganisms? Even if impeller pumps do shred
microorganisms, I wonder if shredded microorganisms provide a comparable
degree of nutrition to coral and fish in the main tank as unshredded
microorganisms?
Bruce Grant
<These same sorts of pumping mechanisms are used for delivering live food organisms in a few of the commercial culture operations I've visited... try them out and you'll see... some organisms do likely get "frappe'ed" via the shearing forces in non-positive displacement pumping mechanisms... they're still very much utilized by filter feeders, saprophytes... Bob Fenner>