How much skimmate do you get?

[likeavillain]

Those of you with nice skimmers (ASM, ER, Deltec, AquaC, becketts etc.) how much wet/dry skimmate do you get.

I have a 50g tank with a DIY skimmer. It does a good job, but I want to compare it to quality commercial skimmers. There are a ton of variables but I just want an idea based on tank size and skimmer type.

[Poolrad]

Good question, I have a built in skimmer to my old wet/dry that I converted to refugium.

I take off a pint of skimmate every 2-3 days with it..

[likeavillain]

Is that thick dark stuff or watery-green?

[jkapit]

180G Reef with 9 corals and 8 Fish, ETSS 800 skimmer which produces 3-8 cups of skimmate per week. On average about 4 cups per week.

[Poolrad]

It is darker watery stuff, not green definately dark brown and stinks..

[Saltz Creep]

How can you compare?
How much skimmate you get is not entirely an indication of performance. It also depends on the bio-load of the tank. The only really valid comparison you can make is between different skimmers skimming the same tank.

[Zoom]

200 gallon reef tank heavy load.
Deltec 851 this is one weeks worth of skimmate the cup is 8" around by 5" high.
http://reefcentral.com/gallery/data/500/125107-17-05_010__Medium_.jpg



This much in three days.
http://reefcentral.com/gallery/data/500/125107-2-05_002__Medium_.jpg

[orlenz]

I have a 100 gal with a 30 gal fuge, and a med to heavy bio load, I pull out about 1 liter of skimate per week, it is dark enough that you cant see through it.

[mogulski]

i pull about a a quart per week with a moderate bioload

[likeavillain]

Originally posted by Saltz Creep
How can you compare?
How much skimmate you get is not entirely an indication of performance. It also depends on the bio-load of the tank. The only really valid comparison you can make is between different skimmers skimming the same tank.

You're right that's what I meant by variables! More pictures!

[KDodds]

I prefer to get very dry skimmate, so I get about a cup of mud/sludge from my MR-4 per week on a lightly stocked (at the moment) 450.

[likeavillain]

Damn, you must have to scoop it out of there!

[KDodds]

Pretty much, yup. ;) You get used to "shovelling it" after a while. ;) IMO, tea-like skimmate is more a waste of water than a removal of waste.

[fkadir]

Amount of skimmate is not indicative of anything apart from how dirty the water is. Put a large enuff skimmer in ANY tank and sooner or later it will stop producing skimmate most of the time as there is nuthing left to skim from the water and it will only kick into action once you feed the tank with some nasty stuff etc etc. IMHO :)

[jimdogg187]

This is five days worth of skimming from my ER CS8-2 RC with a BETA pump on my heavily stocked 125 FOWLR. The cup is 8" around, and about 4"-5" tall.

http:////reefcentral.com/gallery/data/500/75364er_update2.jpg

[melev]

I have a ER 12-2, and the collection cup is 12" wide and 5" tall. I pull out at least 1g of skimmate every other day. Sometimes it is daily.

I clean the cup every 48 hours, no matter what. Here's the monster.

http://www.melevsreef.com/pics/0505/full_skimmer.jpg

Here is one session, after running Tunze Silphos in my tank to remove Phosphate.

http://www.melevsreef.com/pics/0605/po4_skimmate.jpg

[KDodds]

Originally posted by fkadir
Amount of skimmate is not indicative of anything apart from how dirty the water is. Put a large enuff skimmer in ANY tank and sooner or later it will stop producing skimmate most of the time as there is nuthing left to skim from the water and it will only kick into action once you feed the tank with some nasty stuff etc etc. IMHO :)

Well, that's not entirely true. An ineffective skimmer will produce less skimmate than an effective one, regardless of suspended organic concentration. As well, individual skimmers can be tweaked to produce more or less on a daily basis, and wetter or dryer. Skimmate production is also lower on newly set-up skimmers and can slow down or halt for various reasons other than organic concentrations.

[jeffbrig]

Originally posted by fkadir
Amount of skimmate is not indicative of anything apart from how dirty the water is. Put a large enuff skimmer in ANY tank and sooner or later it will stop producing skimmate most of the time as there is nuthing left to skim from the water and it will only kick into action once you feed the tank with some nasty stuff etc etc. IMHO :)

I could not disagree more. My 3 month old 250g setup has no fish in it, just LR, hitchhikers, and snails. I do not feed anything in the tank regularly. I have fed tiny bits of shrimp to a mantis, a crab, and a curly Q anemone, maybe 1/2 a shrimp TOTAL in 3 months time. Based on your statement, I shouldn't be pulling skimmate anymore. Yet, somehow I find myself dumping about a gallon of skimmate each week (it was a gallon of skimmate every other day when the LR was fresh). I am running a Euroreef 12-2 RC (same body as Marc's skimmer above)

[WifesaysImnuts]

I get about 4oz of really nasty dark brown gunk per day out of Aqua C EV180.

[NoSchwag]

Originally posted by fkadir
Amount of skimmate is not indicative of anything apart from how dirty the water is. Put a large enuff skimmer in ANY tank and sooner or later it will stop producing skimmate most of the time as there is nuthing left to skim from the water and it will only kick into action once you feed the tank with some nasty stuff etc etc. IMHO :)

I agree.. Granted I don't have 1000's of posts but I do consider myself a very logical person.

If one was to get out all the junk that is stored in their rocks, get rid of their sandbed and have no bio-load what-so-ever, I would think that the water would be as clean as it could be.

How could you skim something that isn't there?

[KDodds]

The point is rather reversed, sort off. There may be something you're NOT skimming, regardless of the size of the skimmer. Of course, if you go really nuts, sure, I guess it would be possible to strip ALL organics out of suspension, but that wouldn't really be desirable since you'd start to starve organisms dependent on such things.

[jeffbrig]

Originally posted by NoSchwag
If one was to get out all the junk that is stored in their rocks, get rid of their sandbed and have no bio-load what-so-ever, I would think that the water would be as clean as it could be.

How could you skim something that isn't there?

The only way you'll get to that point is if you introduce no food sources, have no photosynthesis occurring, and no food chain established in your tank. In reality, algae grows in your tank, even a clean tank. Plenty of things eat algae - snails, pods, hermits, etc., and produce waste as a byproduct. What about all those worms living in the rock. Feather dusters that filter feed and release regular puffs of detritus into the water. Bigger things then eat the pods, sometimes snails (mantis anyone?). Everything that grows is using a food source and contributing waste. There will always be something to skim, unless there is nothing living in your tank.

[AquariumPerson]

I have a Oceanic Model 6 Protein skimmer on my 125, its cup is around 6" wide and 6.5" tall and it fills up about 3/4 per week with dark brownish sometimes greenish stuff that is like dark tea. well, kinda. All i know is it smells horrrrible...waaay worse than the skimmer gets out on my 75g.

[fkadir]

Originally posted by jeffbrig
The only way you'll get to that point is if you introduce no food sources, have no photosynthesis occurring, and no food chain established in your tank. In reality, algae grows in your tank, even a clean tank. Plenty of things eat algae - snails, pods, hermits, etc., and produce waste as a byproduct. What about all those worms living in the rock. Feather dusters that filter feed and release regular puffs of detritus into the water. Bigger things then eat the pods, sometimes snails (mantis anyone?). Everything that grows is using a food source and contributing waste. There will always be something to skim, unless there is nothing living in your tank.

Im not saying that there will be no skimmate day after day but rather that the proportion of skimmate is not indicative of the performance of the skimmer. It just indicates that the water is laden with organics and thats why ppl are getting a gallon a day of dark skimmate etc etc.

If the skimmer is efficient enuff,after a period of time, water quality will be top notch with very little skimmate produced on a daily basis (depends on bioload etc etc). There should be a daily period where the skimmer just sits there and stop producing brown skimmate waiting for the level of organics to build up again. Makes sense?

So those with a cupful of skimmate every day is either feeding very very heavily or have a very high bioload or both.

[KDodds]

Again, not totally true. A lot of people like an extremely wet skimmate, that looks like weak tea. Nothing wrong with that, but the organics concentraion doesn't get built up enough on the bubbles to make it as efficient, thus LESS is actually removed daily, IME, than with a drier skimmate. For instance, changing nothing but the water level in the skimmer, I got 1/4 cup of sludge out of my ETSS Evolution 750 on my 180. Changing it again, I filled about a quart and a half of wet skimmate in a week. Allowed to evaporate, the same skimmer produce less than 1/8 of a cup of sludge. Anyway, it produce more volume of output, but removed less solids. Just by changing the way in which the skimmer worked, not by altering bio-load or feeding or lighting or anything. And yes, I repeated the results. SO, output of a skimmer is actually dependent MORE on how it's set up than on what it's actually doing or what the water quality is (within a given system's and skimmer's abilities).

[fkadir]

Kieron, What if you have set it up for dry skimmate and you do not feed the fishes and have only 1 or 2 fishes in a 500g BB tank with reef ceramics for rocks and thus minimal biological activity on a daily basis. Would you expect to get 1 cup of sludge everyday, day-in and day-out without an eventual tapering off of slimmate production?

[KDodds]

When you spend 20k or more to set up that tank for a couple of Percs, let me know, I'd love to see the colossal waste of funds. ;)

But to answer your question, you'll have a baseline skimmate production for that system that can be played with by adjusting the skimmer. Whether you feed enough for the 2 fish, or for 20 fish, daily, would have minimal impact on skimmate production as a whole in such a system. The "minimal biological activity" you suggest simply will not continue in stasis. It's the nature of life. It will fill the niches it can fill. Algal films will form, algae will grow, bacteria will colonize, cannibalize, whatever they have to do to survive. Relatively quickly, your "minimal biological activity" will begin to produce excess organics, releasing into the water column for removal by a skimmer. This will cause a gradual increase in skimmate production over time, over the "base line", if the skimmer is not fiddled with.

What you're trying to say is that it is possible for a skimmer to remove close to all of the organics in the water column, at which point it will stop producing skimmate, correct? What I'm saying is that this is not necessarily the case. In fact, I don't even think it's possible. For it to be possible, you would have to insure that every DOC and DOM present in the system at least passes through the skimmer. This would, IMO, require the skimmer to be directly gravity fed from an overflow. Coagulants would then have to be used to force DOCs and DOMs to float to the surface to flow down the overflow and into the skimmer. And even still, I think it's pretty much a guarantee that at least SOME will escape back into the water column.

Now, you're getting into a more interesting area. Is a skimmer design for a larger system going to work MORE efficiently on a smaller system. IME, to some extent, yes. However, being designed for a larger system would also mean that flow through rates change, mixing time changes, etc. Although there's no hard evidence either way that I know of, it makes much more sense to me that this skimmer would reach a plateau of efficiency due to its design limitations before it will have "completed its work" and stopped producing skimmate, regardless of bio-load. IOW, just because it's rated for a larger system does not mean it will be capable of removing the equivalent amount of gunk in skimmate in a smaller system.

Going back to bio-load. Would you consider a 450g tank with 7 fish, most 3-4" and 2 6-8", 700lbs of rock, a DSB, and a 180gal refugium to be high bio-load? Moderate? Light? Yet, this is the system producing 1 cup of sludge per week. Which brings us back to your original point. From experience, I know that this skimmate production will NOT drastically change as I build up stock. What's IN the skimmate MIGHT, I have no idea, but the production itself probably will not. Why? Well, it's a natural system. As nutrients become more available, more organisms proliferate to take advantage of them. Down to the minutest organism, mass and energy will be exploited to the advantage of those organisms most efficient at doing so under the current circumstances. Because of the bio-diversity in such a system, and because mass and energy used will eventually be released, in smaller amounts or not, other organisms exploit the excretia of "higher organisms", breaking things down into simpler components, building them up into more complex materials, etc. What is used is reused, what can be exploited will be exploited. The net effect is very little change to "unused" organics actually reaching teh skimmer for removal. Just what I've seen over and over again. Yes, sure, there's a line, especially with fish bio-load, that can tax a skimmer's efficiency. And, yes, a "better" skimmer might remove more organics in such an instance. But, it remains untrue that skimmate production can correlate directly to bio-load.

[likeavillain]

I find it very hard to believe that any of us are skimming to the point that DOM rather than the skimmer itself is the limiting factor in skimmate production. I have heard too many accounts of substantial skimmate from minimal bioload systems: BB with fully cycled/"cooked" rock and no livestock, new systems, etc.

If you aren't gettting much from your skimmer anymore, I bet if you added ozone or increased dwell time you would see a big difference in what you can pull out.

Enough skimming theory. Read the Calfo skimming thread. Back to the topic...