New Skimmer Concept - will it work?!?

[stugray]

I was just wondering.....

What if we ran a skimmer very wet and 'recycled' the cleanest part of the skimmate back to the tank? Could we make a skimmate concentrator?

I was imagining a skimmer with very wet skimmate. When the collection cup filled to the proper level, then SOME of the skimmate would go back to the tank.

The question is: Can we find a region in the collection cup that is cleaner then all the rest of the cup? Maybe by the way the detritus settles.... If we pull from the middle can we get cleaner water?

It just seems that if you could make this work, then you could run a skimmer as wet as possible, and just flush the collection cup when it is 'nasty enough'. I even think you could run a auto-wetneck using this concept.

Thoughts?

Stu

[A.T.T.R]

why not dry skimm the wet skimmate and slowly does that water back to the tank ( the water in the 2nd skimmer not the 2nd skimmers skimate)

anyways why?

[Kolognekoral]

Stu,

there is a theory (?) that it may be possible to create a more selective skimming via a change in the uptake tube (reaction tube). This is part of the principle behind the new Korallen-Zucht skimmer. The tube is conical. Some skimmer cups already have this form. I don't know if it brings anything at this point in the skimming process, though.

As to whether this is actually working, I am unsure...therfore take it for what it is.. a new design.

The idea is exciting, as we currently have only the options of wet and dry (kinda a poor description choice, don't ya' think?), which really means changing the time in the reaction chamber. I skim wet, as this actually removes more ( a wider range) from the water column, but more of what is the question. Certainly, some of what I remove is from the positive side of the equation.

It is known that a portion of the organics in the skimmer do escape back into the water column in a reverse-flow system. I don't know the statistics.

On the purely technical side, this ia a very interesting area of study, but the practical apllication may be of little real value.

[H20ENG]

Everyone says the cone skimmers really kick butt. I am failing to see how the reaction chamber shape can affect skimming that much. I can see a great smooth transition helping to push the foam up and out, but I'm interested in learning more about these.

Stu,
I'm wondering how you could get the water JUST from the middle of the cup without using a solenoid valve, etc.

[stugray]

H2OENG,

"I'm wondering how you could get the water JUST from the middle of the cup without using a solenoid valve, etc."

How about this:

The skimmer neck has an inner & outer cylinder. The inner is the riser tube with wetneck ports, and the outer cylinder forces water to be pulled from the middle of the collection cup to go back to the tank & feed the wetneck.

Heres a pic. The dashed horiz line is the water level. Once the level in the collection cup reaches that, it will start dumping back into the skimmer body via the wetneck ports. If you run it wet, will you get a more effective skimmate????


http://reefcentral.com/gallery/data/500/60772skimmer_riser.jpg


Stu

[H20ENG]

I see. Thats going to be a hard sell to get people to put skimmate back in their tank. Great thing to think through, though.

I wonder how much more junk you remove by skimming real wet?

[ahullsb]

I think that is an interesting concept stu.

[Kolognekoral]

Linking to zeovit board now allowed......Nanook


Check out this thread on the Zeovit forum. There are lots of interesting links to skimmer related articles.

[rf]

I have a Skimmer with a collection cup discharge tube that runs to a 2" PVC Reactor full of Carbon and the cheap nylon woven matting. The wet skimate flows at probably 2-5 gallons per hour. The water pushes through the PVC leaving behind any waste. Clear water comes out the other side of the PVC back into my sump.

The only real benefit I have noticed is not having to clean the waste cup every day. Water quality is the same whether I collect in a waste storage container or send it throught the PVC filter back to the sump.

[geoxman]

So why not just use carbon and some floss filter in your return? I guess I am not grasping what you are doing

[stugray]

H20ENG,

"Thats going to be a hard sell to get people to put skimmate back in their tank"

I was noticing when I adjust my skimmer, occasionally it runs amok and skims way too wet. When this happens the collection cup fills up to the top of the riser tube, then dumps back to the skimmer via the riser tube ( much like a wetneck ). BUT it keeps on skimming!

Sometimes this wet skimming can generate a LOT of skimmate, but the top layer is just dumping back to the skimmer. I think the top layer is the most highly concentrated skimmate ( it hasnt had a chance to settle out ).

If you could selectively pick which layer you send back via the wetneck ports, youd get a 'regenerative skimmer' AND the benefits of a wetneck.

Stu

[David MC Lee]

I have thought about something like this too. But take the wet skimmate and run it through like another tank with mangroves or some sort of algae that would take up the nutrients.

[hahnmeister]

I just use this as an opportunity to do small water changes on a regular basis.

[kydsexy]

silly skimmer users...............

[stugray]

"silly skimmer users..............."

Well here's my opinion: While I was experimenting with my DIY skimmer, I had major problems getting it to skim consistently. While the skimmer was "under-producing" I was having problems with: Red Cyano outbreaks, Nuisance Hair algae ( EVERYWHERE ), Whole colony coral die-offs, and general reduction of coral growth and coral shrinkage ( I even lost an Acan that was flourishing previously).

Since I got the skimmer working again ( It was a skimmer feed problem since I feed the skimmer via overflow/gravity that has been fixed ) , the skimmer is working fabulously ( I can get a quart of nasty skimmate daily if I run it wet ) AND all of the corals that were in decline are now coming back, the red cyano is almost gone, and the hair algae is also in decline.

Coincidence? I think not ( espescially since I CAN get a quart of coffee colored skimmate per day ).

Can you imagine this skimmer collection cup full of coffee?

http://reefcentral.com/gallery/data/500/607725gal_bucket_skimmer_1_small.JPG


Back on the original topic: I set my skimmer to run a bit wet last night. This morning the cup was full enough to flow back into the tank over the lip of the riser tube and the skimmer was blowing foam out of the lid of the skimmer! I think my theory of wet-skimming/return to skimmer/wet-neck is working. Now I am about to install the riser tube with the feed tube as in the pic above.

Stu

[A.T.T.R]

stu your idea will not work as you say

you have a sealed top on te part that is covering the holes.. so water has to go down then come up and then into the holes.. so you really arnt getting the top layer

i have one skimmer that uses a seperate collection cup

i skim on the dryer side but knotice that thetop layer of water is clear and the farther down i go the dirtier it is. i know alot of thinks float and are probobly at the VERY ( like an oil slick) but the majority of the top layer seems good
( this cup takes a week to fill i might add so it has time to settle)

let me draw up my idea

actualy nm your idea is exactly what i was saying. drawing out the middle layer of water

[stugray]

Ok,

here's a visual. Here is a pic of my skimmer collection cup when it is skimming 'wet':

http://reefcentral.com/gallery/data/500/60772skimmer_cup.jpg

And here is a pic of the new riser tube I am about to install:

http://reefcentral.com/gallery/data/500/60772regen_riser_tube.jpg

As you can see the water will flow from the middle of the cup, up and out of the 'wet-neck ports' drilled around the perimeter near the top instead of over the top like it does currently.

BTW - the riser tube in my skimmer comes out easily. It is just press fit in place in the collection cup, so I can remove it to clean or experiment with different lengths....;-) That has been VERY handy!

Stu

[H20ENG]

ATTR,
Stus neck will grab the water in the middle of the cup, not the settled, or floaties:)

[stugray]

Update:

I put the new 'concentric-riser tube' into the skimmer, and it ran great with the usual setting while breaking in. I even dumped a whole quart that it pulled out since yesterday before turning it up to skim wet.

Here's a pic ( I mostly let it fill up then turned it back ):

http://reefcentral.com/gallery/data/500/60772wetskim.jpg

From the pics, you can see that the collection cup fills to about 1/2" from the top of the riser tube, then the level stops rising because of the wetneck ports allowing water to flow back to the skimmer ( inside ).

I'll wait a day or so & see if the skimmate gets darker.

Stu

[FFrankie]

So basically your just recirculating the skimate. How about multi stage skimming to get a concentration as the end result and less water waist? Great thread everyone.
great diy skimmer btw Stu!

[hahnmeister]

Or, just skim dryer in the first place... thats what I was thinking. Its not like the 'recirc' neck actually does anything until its full anyways, you know? By the time it fills up that far, it needs to be removed for cleaning anyways.

Otherwise, what you could do is have dual skimmers... one on the tank's water, and the other plumbed so its only incoming water is the skimmate from the first skimmer.

[Fishbulb2]

A concern that I have is that the hydrophobic organics that we skim can break down and eventually form more soluble compounds. Do we want to keep a direct path between our skimmate and the aquarium? I think it's really cool that you built this thing and that you can try it out but I'm not sure if recycling skimmate is really worth it. I don't mind cleaning out my collection cup twice a week but maybe on a larger system it's more of a chore. I find my skimmer definitely works best if I clean it often.

[stugray]

Hahn & FFrankie,

"Or, just skim dryer in the first place... "

Thats what I do now, and it always seems that I would get more crap clogging the riser tube than I get out with draining the collection cup.
If you clean the tube VERY regularly, then that works fine.

However, if I can find a way to get the same layer that would normally stick to the riser tube, laying on the bottom of the colletion cup, then I'm for that.

The only way this will work, is if the detritus settles into a nice layer while kind-of clean water makes it back to keep the riser tube clean-er.

I'm already thinking that a 'hat' on the riser tube would drop the detritus around the outer edge of the cup & keep it from getting sucked in.

Stu

[hahnmeister]

Sounds like a good-ole wetneck to me. Fishbulb2 brings up a good point as well. The 'proteins' that might be harvested by the skimmer one day can break down into substances which cant be collected by the skimmer. Skimmate smells pretty fresh when you first collect it, exactly like seafoam which it is. The first day it doesnt really stink. After a day or so when the bacteria go to work, the stink starts up. Once at this point, putting it back into the water of the tank would mean that alot (not all, but much of) of waste will get back into the tank, and not be able to be recollected. Thats why I suggested the dual inline skimmer idea...

That way, fresh skimmate could be sent to another skimmer right away to be reskimmed ASAP, if not too late already. This way, it works all the time, and you arent going risk anything old getting back into the system. Think about it, you wouldnt even need that large of a skimmer to just skim the skimmate... perhaps just taller for better 'scrubbing' than the first skimmer.

Heck, thats another idea... try a tall skimmer (with wetneck). I have never seen a 5'+ skimmer skim light, almost no matter how wet you set it.

[Ed Ricketts]

two points

Skimming efficiency is determined in part by the continued rise and collapse of foam created in the reaction chamber. It rises, due to sequentially concentrated amphipathic molecules (proteins and such) higher and higher up the column, until it spills over the top lip filling up the top collection cup. Want more conentrated skimmate? Run dryer. OR place a foot tall neck between the body and the collection cup. Taller column, longer rise for collapse and formation of progressively concentrated skimmate.



Point two: STUGRAY: Can you start a thread of send me a PM about your suuweeeet DIY skimmer. I'd call it a "bucket" rather than a "Beckett" Skimmer :)

[Saboral]

What if you applied the idea of a settling tank. The skimmate and organics are much like the sewage in your septic tank. As it sits the heavy organic laden compounds settle the the bottom as sledge, much like the thick sludge that forms in the bottom of the collection cup. Now by using a long narrow rectangular tank with something like 25+ baffles to slow the water flow you could theoretically seperate the heavy organics from the water, then at the end of the box have an put set at the appropriate height in the column to neither absorb the organics on top or the sludge on the bottom. Then using a siphon to occasionally remove the sludge buildup.

[hahnmeister]

Sounds alot like the horizontal skimmers. Otherwise, a very tall skimmer body would be another way to reduve drainage, yet get darker, more concentrated skimmate.