To skim or not to skim??

[wombat1]

I'm planning a 40 gallon SPS tank with a 40 gallon refugium with maybe mangroves, and definitely lots of xenia, anthelia, macroalgae. I want a huge fuge to help feed the corals and keep nutrients low. The tank will be lightly stocked with fish, just a maroon clown pair. I have a Euroreef CS6-1 but I'm considering not using it. I've heard skimmers keep plankton out of the water column by their action so it seems like if you could get away with one your corals would be happier. I've seen some great tanks w/o skimmers that had LPS corals but I've never seen anyone try it with SPS. Has anyone tried this???

 

[Reefguide]

I don't skim anymore... too many freaking micro bubbles even with baffels in place... I've been running a fuge for a while now and have had issues with slime but I dont think they relate to the skimmer... I don't have SPS but my reef is kicking...

 

[CraigLampe]

interesting, I thought every coral tank needed skimming...

Although I have been moving corals (less light-requiring ones anyway) into our fish-only tank for about a month and although the surface occasionally gets a bit slimey, things are doing well!!

 

[EmilyB]

:lol:

There are different methods of nutrient export.

One is an efficient skimmer..... 8)

 

[skylsdale]

...another consists of various methods of more natural filtration. Our tanks--and the corals in them--are starved when it comes to the amount of nutrients and food that would be found on a reef. We can dump gallons of DT's into our systems, but it's still a Hollywood diet compared to the wild. Why strip away even more nutrients that our tanks are already lacking? Yes, the stuff a skimmer pulls out may look nasty, but to corals and various other organisms this stuff is an absolute banquet.

I would suggest setting the tank up without the skimmer(it's not the cirtical piece of the puzzle that many think it is.) If you need to, you can always plug it in...but I have a feeling if you do things right there will be no need to. If you're really curious about what happens when you cross over to the "dark side", check THIS place out.

 

[wombat1]

skylsdale, thanks for that great link!! I think I'm going to start with it on, then remove it and see what happens. This tank won't have corals for another EIGHT MONTHS. In the meantime I'm just letting detritivores, plankton, etc. build up good populations by feeding the tank with no fish in it. I hope to see good results :wink: BTW, the soft coral tank that we have at the university here is way underskimmed (a remora pro on a 180) and they feed natural plankton and use natural, unfiltered seawater. Awesome growth!!

 

[esmithiii]

I am a firm believer in a skimmer as insurance. It is also great for oxygenation.

Ernie

 

[skylsdale]

It is also great for oxygenation.

Actually, the oxygenation factor is highly debatable....and often times false, depending on the source of oxygen the skimmer is using(e.g. stagnant under-sump air.) I have also heard reports from a conversation with Rob Toonen that bring up quite a few points on this issue that most people probably don't know or realize.

Wombat, to be honest, it is generally MUCH more difficult to wean a system off a skimmer than to add one later on. Why? Because as your system stabilizes, it does so with the skimmer as an integral part of the system. When you take that out(which most people do cold turkey) it can wreak absolute havoc on your tank, usually causing intense algal and diatom blooms(which people now associate with pulling their skimmers, although it doesn't need to happen this way when done right.) If you start your system skimmerless in the first place, the skimmer never becomes a part of the equation. If down the road your tank becomes some kind of rotting cesspool, you can then add the skimmer to it...but I have a feeling if your tank has gotten that bad, it's more of a husbandry issue and no piece of equipment is going to help. Feel free to ask whatever questions you have over with the skimmerless guys--they are MORE than happy to share their experiences and knowledge with you.

 

[jhaag]

I've been running a 90gal with a 30gal sump/refugium setup basically like the EcoSystem (less the miracle mud) for over 60 months now. It basically LPS and softies, but I have never seen my corals looking this wonderful before. I did run a 29gal and a 55gal both with skimmers before my latest setup. Now that I have seen how a skimmerless tank with lots of macro algae for export performs, I don't think I would ever go back. The only exception I can think of is SPS. For some reason I though that the ecosystem type of setup wasn't the greatest for SPS, but it is absolutely amazing for softies and LPS.

 

[skylsdale]

The only exception I can think of is SPS.

Eric Borneman seems to be doing fine with SPS in all of his skimmerless tanks.

 

[gooch]

Most of my tanks,actually all but one are skimmerless. I have about 100 types of sps' and probably close to 500 corals. My observation on skimmers is this. Not needed but it is the quikest way to turn around a tank having problems.

The only tank I have that has a skimmer is without a refugium so I error on the side of safety with this one and run my euroreef cs6-1. The water is the clearest of all my tanks. I will be attatching skimmers to all of my tanks eventually but will run them only when I feel the tank needs a good cleaning.

Also Borneman doesn't run skimmers but has them in place just in case.
Reason I know this is its what he told our club this weekend.

gooch

 

[reefNewbie]

so the only filtration you use is your LS and LR? How often do you do water changes and what amount?

 

[gooch]

Yes, my only form of filtration is the sand,rock,macroalgea,clams,corals,shrimp,snails,crabs,reef bugs,anemone's and fish. They all play a part in the cleaning of my reef aquariums. I have performed exactly one water change on my tanks in the last six months. Do I recomend not doing water changes. Absolutely not. I fortunately will have to perform water changes quite often now since I now sell corals and have to replace the water that gets taken away by customers. I also don't believe the crap about not being able to mix soft,lps and sps corals in the same systems. Many of my tanks are connected and all are mixed.

I do run activated carbon from time to time. Always while I cycle a tank.

gooch

 

[Anonymous]

A good compromise is to run an undersized skimmer.

 

[wombat1]

It seems like skimmerless is the exception, rather than the rule, but I like the idea of using technology for only what is absolutely necessary: pumps and lights. The concept of natural methods to clean the water and promote a healthy livestock seems to be the direction this hobby is headed in the future.

 

[SPC]

Posted by Sklsdale:

Eric Borneman seems to be doing fine with SPS in all of his skimmerless tanks.

-Has Eric actually published anything on the merits of going skimmerless or has he just mentioned it from time to time? I find it very difficult to believe that he is advocating people go skimmerless.

...another consists of various methods of more natural filtration. Our tanks--and the corals in them--are starved when it comes to the amount of nutrients and food that would be found on a reef. We can dump gallons of DT's into our systems, but it's still a Hollywood diet compared to the wild. Why strip away even more nutrients that our tanks are already lacking?

-This is correct, our corals are starved in our tanks compared to what they recieve on the reef. The problem with this line of thinking however is that they are not necessarily starved for the organics that the skimmer pulls out.

Yes, the stuff a skimmer pulls out may look nasty, but to corals and various other organisms this stuff is an absolute banquet.

-Do you have any scientific data to back up this claim? Do you know of any data that shows exactly what is in skimate and what proportion of it could have been utilized by corals?
Steve

 

[NaCl-H2O]

I've been skimmerless for 6 years on the 72g and 3 years on the 125g and all is well, good health & good growth. I keep SPS & LPS in the 72g and LPS & softies in the 125g. I use a larg refugium full of caulerpa and a DSB in the show tank and in the refugium on each tank. I also do 5g water changes on both tanks every month and feed my corals. The caulerpa keeps all my readings down to 0 and helps with organics. I harvest it bi-monthly. I think a well maintained tank, compensated with some other types of more natural filtration(alge scrubbers, refugiums/w/caulerpa, DSBs, Pleniums, water changes, etc..) doesn't need one and is probably heathier in the long run, but every one should have a hang on for catastrophy control. There are situations that could happen to any tank regardless of setup, that a skimmer could help with in a pinch. This is a result of my experiance and my opinion. But not my opinion and experiances alone. Many of the experts also don't skim. But when it gets right down to it it's YOUR tank and YOUR choice.

 

[danmhippo]

I have been going skimmerless in my 150G. The two sump I had is 45G and 35G, and they are fully stocked with caulerpa so thick that I cannot see past 1" of the glass. The main tank is primarily gorginions and softies. I am never a big fan of sps and lps.

The tank has been skimmerless approaching 3 years. One thing about going skimmerless is that you need to have a efficient nutrient export via other non-mechanical means (macro algae, for example). In addition to that, due to the yellowing agent macro's typically releases, you will need to perform waterchanges religiously. Otherwise, everything else is the same as the skimmer-ed tanks.

One of the biggest benefit of skimmerless, IMHO, is liquid and small invertibrate food gets to stay in the water much much much longer than systems with skimmer. You can afford to feed less. If you have habits of using live phyto's, you are less likely to waste your $$ for your super expensive DT's to wind up in skimmates.

 

[skylsdale]

Many of the subjects that will probably be discussed here have probably been covered in this soap opera. It really doesn't get constructive until around page 6, and Eric Borneman jumped in around page 7. Here are a few of his comments:

What I will add is my somewhat extensive experience and some basic reef ecology.

First of all, I have not run skimmers on tanks for years. There's nothing special about this. Anyone who has run a Jaubert or ATS tank does the same. Skimming is not required for successful reef tanks, and it does not necessarily imply the tanks are higher in dissolved nutrients, are limited in fish load, coral types, etc. That's just a fact, and given what I look at in my home every single day since 1994, I dare anyone to say otherwise. Its neither novel nor unusual for people to do this.

That said, there are tanks with skimmers and without skimmers that are a mess, and those that are healthy and pristine.

To say that the gunk skimmers remove needs to be removed is outrageously wrong. Why? Because it looks and smells bad?

Think about it. On the reef, food consists of relatively few things: zooplankton, phytoplankton, dissolved organics, particulate material, and bacteria.

Our tanks are notoriously low in zooplankton and phytoplankton. That means the other things have to make up the lack. What does your skimmer remove? The rest of the food.

Yes it looks and smells foul. So does bacteria, fish poop, and coral mucus, three dominant parts of what most sessile filter feeding invertebrates, including corals, use for food. You are skimming out waste material that seems foul to us, but is food to other animals, however disgusting it might be.

Are you skimming out unwanted things, too? Sure. Possibly allelelopathic chemicals, excess metals and excess dissolved organics. Guess what else does that, and does so effectively? Activated carbon. Plus, it leaves the food in the water.

Tanks without skimmers have higher amounts of particulates in the water, and this substitutes for plankton. I know that it is easily possible to feed heavily and have ridiculously low nitrogen and phsophate levels in the tank and non-yellow water without skimmers.

So why skim?

Because to run skimmerless you need either significant uptake or to do water changes. I don't do many water changes, though I don't recommend this. It will be harder to have a tank relatively devoid of sand, rock, algae, sponge, coral and other sessile inverts and feed havily without a skimmer. For most reef tanks, this is not the case. If algae grows, get more herbivores.

There is however, a lot to be said for skimming...it is a safety net for accidents and deaths in the tank, it provide extra flow in tanks, extra aeration, etc. I happen to be at near saturation for O2 day and night because I use surges, have a lot of overflows, and a lot of surface area and a lot of surface turbulence, so I don't need skimming for that purpose. I do have a skimmer inline on my big tank for when I go out of town in case something happens. Unfortunately, I have forgotten to turn it on in the past and things have happened. I also use a skimmer on my lab tanks becasue I don't trust anyone but me to not do something wrong.

Bottom line, skimmed tanks work, unskimmed tanks work. Up to you.

Its my experience that our systems are capable of great flux, just like in the wild, and that we may have death, regrowth, reallocation, and successions and that if we sit back and watch, they all come and go, passing, renewing, and changing. I like that. I mean, if its a goal to have a set set of growths with no losses and no blooms, etc., then intervention is probably required. But, I don't look for that. I like watching the changes, for better and worse. Losing animals in a reef tank, so long as it is not by negligence, is part and parcel of it all.

I liked a quote at one of the MACNA lectures about starting a tank, putting in a bunch of frags and seeing which ones live and die....the ones that live are well adapted to the tank and grow...the ones that aren't die and aren't replaced. Same thing happens on reefs. I think this is a good philosophy to adopt.

>> So if I understand you, you are saying export is not absolutely necessary given adequate uptake? If that's the case, again correct me if I'm off, any tank based on that system would (theoretically) eventually burst due to ever increasing biomass - if one is lucky enough for the uptake to be something other than algae.<<

Yes, eventually it would "burst" - see above comments and include the possibility of life and death scenarios. IME, corallines, substrates, coral skeleton, and animal and plant growth seem to be enough over long scales in tanks.

>> It seems many of our problems then are due to lack of herbivory - care to shed a little light for all of the recurring hair algae combatants out here? I suppose 99% of the battle is never having it in the first place (getting a foothold)...Seems like too delicate a balance for many to even have a chance with.<<

Turf and filamentous algae grow very quickly on reefs, but there is so much herbivory, you never see it. It takes up nutrients and sunlight, and then goes intot he growth and reproduction of herbivores..waste from them is eaten by worms and corals and sponges..by tiem you go through the whole chain, very little is - or should - be left. Any remaining excess seems able to be sequestered or accumulates at very low rates - but, this is my experience and/or what is possible, not necessarily or perhaps even likely to be what happens in other cases. I know that others achieve the same and better, so its far from impossible.

My lab tank, I am finding, is having a hard time with enough algae. I am feeding heavier and heavier and have snails, a blenny, nassarius, and Mithrax. I had to remove the Mithrax because it started eating coral tissue for lack of algae. I have increased an auto feeder to 12 5-second bursts of Golden pearls a day (estimated about 1/16 teaspoon each) and adding phytoplankton and 3-4 cubes of frozen food a day - 55 gallon tank. I cannot get any filamentous algae growth to appear, even temprorarily until the snails find it, and I assume my herbivores are somewhat hungry.

I am geting more and more convinced that the "old-tank" syyndrome and the death knoll for many things lies not in nutrient accumulation but in toxin accumulation, be it organic or inorganic. Ron's talk showed evidence of thisin terms of metals and salts - yikes!!. Randy Holmes-Farley intimates the danger of organics and I have long bantered about the toxicity of various algae, snails, soft corals, and now even stony corals, cyanobacteria, bacteria, sponges, tunicates, fishes, etc. I think this is really the area that needs the most addressing in the future. I don't think nitrates and phosphates are killing old tanks slowly as the water tests so low...I think its all the animals and plants in a closed system that we have gotten so very good at getting to thrive and putting in competitive situations.

On the toxins/allelopathic chemicals/secondary metabolites....

There is a wide range of effects in both degree and specificity - some are general poisons, some are very specific, some we have no idea. Many are very complex chemicals and have all sorts of metals and halogens in them.No telling what happens as these things "break down." I think the tanks are too complex with too many species to accurately predict or even know what is happening, and no tests will ever be conveniently available to us.

I also don't think uptake is a good way to deal with these. For one, it doesn't seem to work, because if I am right in this, then old tanks, if any, should be able to do it. For another, many of these compounds have certain actions - i.e they work on specific cellular processes, so uptake may mean cumulative or chronic effects. I think the best way is removal, and though I suspect though am unsure of the efficiency of skimming in doing this, I know that carbon can remove them..maybe not all, but this is one of the things that scientists use when doing studies where secondary metabolites must be controlled - activated carbon.

And of course, water changes work. The metals issue is a whole nother ball of wax, cause salt mixes seem to be a major source.

I don't think there is any "glory" in trying to keep a successful tank in one way or the other outside a healthy way. If I see the tank suffering by my hand because I put these things in a tank, I'm going to use every means at my disposal to keep the system healthy - be it algae, skimming, water changes, carbon, miracle mud, toxin-vital, prayer, satanic encryptions, or whatever. This doesn't need to happen frequently, but I won't watch a tank crash because I want to say I have a system with "no export."

Alright, there was a lot said there. Basically, Eric sees the merits of both methods--as do I. He hasn't just mentioned it from time to time, but actually practices it on a regular basis(pics can be seen on his website.) However, he does keep one on standby to help with any major problems that could arise, which I think is smart husbandry on his part. My problem is the fact that so many people see a skimmer as a necessity for a successful tank, while it is obvisously not. He also articulated the emphasis on particulate matter that is important to coral feeding, where many particles take the place of plankton in our captive systems, and are still devoured by corals.

The conclusion is basically that there needs to be some form of export, whether it be through macros or water changes. Personally, I don't like caluerpa or macro algaes. The tank I am currently setting up will be skimmerless and free of macro for nutrient uptake. It will rely on sponges, tunicates, bivalves, and various other filter feeders for the uptake of DOM. I will also carry out water changes to help provide in the export of some things from the water column, and an occasional harvest of sponges, etc. to export these elements that have been locked up in the organism's biomass.

As far as what's actually in the skimmate, there has never been a scientific study done on this, so no one knows exactly what's in there. I would also venture to say that every system will be different in it's results, so it is impossible to make a hardline guess as to what skimmers do and do not skim(although many would probably try.)

Overall, I think too many of us try to recreate the "perfect" environment, and we try to prevent nature from taking its course in our tanks. One of the biggest things I have taken from what Eric has said is that our tanks engage in cycles and fluxes, just like the ocean. Rather than trying to "fix" these changes, we should sit back a little and see what happens--let the environment bend a little bit.[/b]

 

[CraigLampe]

I agree that the environment in the reef must bend a little bit, sometimes people see my tank and note all of the microalgae and think that I am doing a poor job of "pruning" but every time I place my hands into the tank I know I am flirting with disaster

I am being overdramatic, but if I were to pull out 90% of the algae I may cause a crash because all of the other organisms are used to the algae pulling nutrients out, placing O2 in the water, and drastic changes at the hands of man seem to cause problems, if I have ONE MAJOR THEORY of reefkeeping/aquariums/pets it is that;

-- STABILITY IS THE KEY --

I think we would ALL BE SHOCKED in what kind of conditions corals/fish/inverts can live in as long as:

1) they get there slowly
2) they stay there for years...

Sometimes when things fall (especially my montipora which is WAY OVERPOPULATED IN MY TANK) I simply let them go, sometimes they will die (small pieces of montipora) and sometimes they will LOVE THEIR NEW HOME!! (current/light/shade/sand/rock substrate!)

anyway, sometimes we have to take our hands out and just enjoy...