Overskimming?

[GTR]

<a href=showthread.php?s=&postid=12597715#post12597715 target=_blank>Originally posted</a> by hahnmeister


There is also the definition of overskimming which is simply when the skimmer (often too large for the system) simply runs out of stuff to skim, so the foam head doesnt even form.

And then the keeper adjusts it to bring wet foam up and over into the collection cup because they have the need to see their $2,000.00 skimmer pull something out of the water. I know, I've been there.

BTW, not sure what it is but I don't think this is about nitrates and phosphates at all. Those are easily controlled using other methods.

SteveU

 

[BrokenReefer]

So to follow along that mindset SteveU, would it be wiser to run a slightly undersized skimmer on a system and make sure that the natural filtration and mechanized filtration methods are up to par?

 

[GTR]

I can't say what would be better. I think much of what is being removed from the tank could be removed with a combination of GAC and a good old filter sock changed on a regular basis.

Again, until we know what skimmers remove everything is just speculation. The problem is their is no incentive for anyone to allocate funds to determine that. Up until now it seems that the "bigger is better" mindset has prevailed.

SteveU

 

[BrokenReefer]

I do agree with you. I've not been in saltwater for too long but what I have seen and done, has altered my original mindset.

I, too, believe that overskimming is inefficient and detrimental to the overall environment we strive to keep, along with not knowing what the green/brown/black/smelly gunk being removed is. Without that knowledge how can we truly know that there is a need for larger than life skimmers.

That being said, to address the OP question. In my mind, I feel overskimming is not a universal and cannot be truly defined by anyone set of generic truths.

 

[ReefEnabler]

I'm actually ending up with a more powerful skimmer for my system than I wanted (check my thread in the vendor feedback forum if you're curious why).

So instead of an ASM G4, I have an E.T.S.S. 800 XR on my 220 display tank. 70 gallon sump + 35g frag tank + 50g refugium + 50g w/c mixing tank (also part of the system) is roughly 400 gallons total. The skimmer will be fed by an Iwaki 55RLT.

I know that ETSS skimmers can be pretty aggresssive so I'm wondering if it might be too much?

Due to my setup, I'm not really able to maximize its performance. They recommend feeding it from the part of the sump where the tank drains to, but the only place where bulkheads can go is in the return section.

So basically I will be feeding the skimmer from right next to the return pump. Do you think that will affect the performance at all???? I will be putting a ball valve on the pump outlet so I can dial it back a bit if needed, but I've heard that the ETSS can be finnicky about dialing back.

 

[GTR]

That's another can of worms. :lol:

My first concern in your case would be micro bubbles being returned to the tank.

SteveU

 

[ReefEnabler]

the skimmer outlet will go over to where the tank drains into, so there are 4 baffles between there and the return section.

 

[BrokenReefer]

I checked out your thread... very impressive setup Ryan.

 

[hahnmeister]

Are you really a 'Lego builder'? I just ask because I know there are those 'Master Builders' who do some pretty amazing things... like 15' tall cranes out of legos.

 

[ReefEnabler]

hehe nope I just put that as a joke. my real job is "Level Designer" which for me really means "3d environment artist". I help make games. I am working for a company called Epic Games.

i might as well be a lego builder since some days I feel as if all I do is move pieces around to see how it looks.

 

[hahnmeister]

Oh, Epic Games... that little company? Gee, they havent come out with much recently... not since UNREAL TOURNAMENT3 or GEARS OF WAR!!! Lol... thats cool stuff, nice job on getting banned in Germany too...lol. I do some level modding myself for Unreal (the low grav bedrooms), Counterstrike, and Team Fortress now. I want your job. I could program levels and just do game design all day... you lucky dog. Need any EE's?

 

[ReefEnabler]

hehe lots of stuff gets banned in Germany, they have very stringent standards for violence in entertainment.

Unreal Tournament 1 ('99) actually had to ship a completely different SKU to germany where all of the players look like robots and all the blood replaced with oil spills In fact thats the only reason the 'war machine' style characters were ever introduced into the regular version too.

level modding is where its at if you want to get a foot in the door. I started out the exact same way and was hired as an intern for Scion Studios who later merged with Epic Games. It was rather lucky I guess.

hehe if I had my way we'd have EEs so that we could start doing other cool stuff too gears needs a chainsaw controller ROFL jk

 

[Reefer Brian]

How about keeping my original subject alive fellas, Im sure there are plenty of gaming forums out there. Thanks for all of your input pertaining to "overskimming". Thanks.

 

[ReefEnabler]

sorry wasnt meaning to get on a tangent

Ill admit Im a skimmer noob. Ive only had skimmerless tanks.

so seems like people are saying that skimming wet has a better chance of overskimming the system.

So if its pulling incredibly dark stuff consistently, could you still be overskimming?

i never liked the idea of wet skimming to begin with. to me it seems like the salinity could creep down since the ATO would keep replacing the pulledout SW with FW. I know you have to check salinity regularly anyways to be sure.

 

[Reefer Brian]

No worries, I am not a fan of wet skimming either. I like it dry and dark. I have found through other threads that overskimming is basically a myth unless you have a 1,000g rated skimmer on a 60g tank. All this info and nothing consistant as far as anwswer go. I guess My skimmer is rated properly for my system so I have nothing to worry about. Happy skimming.

 

[jankytomato]

Just a couple of points to throw in:

Pretty certain skimming won't remove dissolved nutrient. Still need macro or media for that.

It seems to be organic particulate though may go down to the size of large organic molecules.

Aggressive skimming seems to be a safety net for those who would like to be able to overstock/overfeed and not put a lot of effort into finding balance and taking it easy.

As a side note, corals can eat that dead organic particulate too just like plankton. They even need a small amount of dissolved nutrient, though the amount is small enough so it should register as zero in the hobby test kits.

Maybe ideally it (skimming) hurts more than it helps from a certain perspective, but keep in mind what would happen alternatively to tanks that are overstocked/overfed/not enough fuge to handle bioload.

It's dangerous to recommend certain aspects of natural methods without the whole picture. Look at what happened with the bastardization of deep sand beds and the fallout from that.:rollface:

 

[SuAsati]

I had an old tank(100G) that I tore down when I upgraded, but never took the water and sand out, still have some live rock and a small cromis in it, never did water changes just top off water for almost a year now. After seeing this thread I decided to put my BM250 which was sitting around back in it and see what happens....

I got skimmate for a few days, very little of it, and the fourth day morning there was no foam, just bubbles bursting out... been like that since... Would like to hear your interpretation.

 

[hahnmeister]

<a href=showthread.php?s=&postid=12621676#post12621676 target=_blank>Originally posted</a> by jankytomato
Just a couple of points to throw in:

Pretty certain skimming won't remove dissolved nutrient. Still need macro or media for that.

Welcome to Reef Central!

Skimming alone can not remove dissolved nutrients, and there are several proteins that are not hydrophobic, so a skimmer cant even touch them, but...

Thats the whole point of several 'low nutrient' systems, like Zeovit, Ultralith, Prodobio, or just plain ethanol dosing. The dissolved nutrients are picked up by bacteria which the skimmer CAN remove, and often does. By doing this, you can strip the water down so much more than a refugium can that you can not only starve your corals, but kill any macro-algae as well.

 

[2thdeekay]

Simple Experiment

Simple Experiment

Here's a simple experiment to try. Ideally, you would need two identical systems (or more), one is used for a control.

1. Document your system well, & photograph your corals, macro-algae, and daily/weekly skimmate. If you have detectable levels of dissolved nutrient, that would be important to record.

2. Maintain your current heavy skimming, and start dosing some kind of carbohydrate. Ethanol, or sugar water will work fine, & cheaper. Drink the vodka for the next step.

3. Stop feeding your system (greatly reduce nutrient input)

After a period of time, say 1-6 months, document changes to your corals, macroalgae, skimmate, and dissolved nutrients.

I've done this before, but would like to see what others come up with.

 

[hahnmeister]

My tank would be dead if I did that... after 2 weeks of ethanol dosing (at rather high levels), my corals were starting to have spot-bleaching and my chaeto was white. I fried one coral after a week because the water clarity improved a good deal and it got too much light. My skimmate doubled from about day 2 to day 10... and then I ran out, and then the bad stuff started happening because I took it too far.

I stopped dosing, and restarted after a week or so of recovery. I ended up at about 1/4-1/2 the dosing I started with (3ml per day per for my 125g), and using it not only makes the water clearer according to the water clarity test I tape on the back of the tank, but it has dropped my nutrient levels... I use less carbon, and have stopped using phosban all together. Part of that though, I do attribute to the new skimmer.