DIY Skimmer design

[Peppie]

I sat down with Mojo today and talked about a DYI skimmer. Of course he set me in the right direction, didnt come up with anything concrete.
I thought about it for a while and this is my " FIRST" design.
OK guys pic it apart, mod it.

The skimmer will be approx. 6'' square and about 17'' to 18'' tall. I like the idea of the air stone, so that has to stay in the design.

I also like the idea of not having a pump to add the water. But flexable on that point.

 

[Peppie]

I need to add , that this will be a part of an AIO filter chamber. So it will be in tank.


Sas. you started me thinking of not interrupting my box last night. LOL

 

[Sasquatch]

good idea they can get a little testy when interrupted lol, not a fan of egg crate, styrene has bad gas, now why not combine so new age crap with this and taper it like a cone?
Water inlet? just a dump or wet neck or multi point? RARARARAAAAAAAAAA!!!!!! gidee up

 

[Peppie]

I suppose the taper could be worked into the upper part of the mixing chamber. Not sure I understand your water inlet methods????
The eggcrate could be replaced with a acrylic plate with holes for the water to pass thru. ALOT i mean ALOT of people use eggcrate with no ill effects. Simple ,cheap, and easy.

 

[Frankie]

Looks like a fun build Pep, Mojo has the bead on how skimmers should be working so your in good hands there. I like the idea with the air diffusers but was hoping to see a build with this new membrane thing he keeps talking about.
For egg-create Sas is correct that the plastic it is made out of contains polymers that break down and release p04 into the water and are magnets for GHA and cyano. Being it is in a skimmer I would not worry though. Light also plays a facto in egg create algae problems. Egg create is thin and designed to let light penetrate it. That's why it looks like it glows when lit with florescent.
The ones that never show signs of algae, it would be my guess that they became "cured" in the water and the outgassing ceased. This is just a guess and ill stick to it until someone proves other wise So I would first cure the create in a high salinity and let it soak for a spell to see if algae grows on it.

It looks like your going to gravity feed the skimmer right? The design looks solid. Look forward to seeing it come alive!
Think "gate valves" for the output~
Frank

 

[Sasquatch]

I suppose the taper could be worked into the upper part of the mixing chamber. Not sure I understand your water inlet methods????
The eggcrate could be replaced with a acrylic plate with holes for the water to pass thru. ALOT i mean ALOT of people use eggcrate with no ill effects. Simple ,cheap, and easy.

water inlet, can be just an open tube but what you get is a single area of supply so with the swirling you could end up with a higher percentage of supply water going back out the exit (thing jet stream) if you built a closed box like a little hallway all around the outside of the skimmer you could drill the inside and have maximum disbursement of dirty water

 

[chickenofthesea]

I am in no way qualified to give any suggestions here but look forward to the end product. I've only been at this for about a year and you guys are light years ahead of me. Good luck peppie!

 

[Skimmy]

so it looks as though the water will b skimmed off the surface and into the skimmer chamber first.... looks good!
you might need more space between the air stones and outlet though to prevent micro's from escaping.

 

[mojoreef]

Dont like it Pep. I was thinking more about that and what I figure will happen is that the air bubbles will ride up just under the plate/slates you have and the water will take the lower path?? if that makes any sense, lol

I think if you go that design you got to skip the staircase.

 

[Peppie]

OK, Thanks guys for all your input. I thinks I have dealt with all the suggestions you have all given.

Sas, I will have water inlets on two sides.

Frankie, Thanks for the info on the egg create. I installed an adjustable slide plate on the water exit. Should be able to reduce the flow with it.

Skimmy, Added more space between the stone and the exit

Chicken thanks this should be interesting to see if I can get this thing to pull skim without busting the bank.

Mojo... Mojo.... Mojo. I am not sure I will be able to please you. LOL I added a diverter tab at the end of each step to slow down the water at that point. I also think it will create turbulence in that area.
I havent cut or glued anything yet . Not untill I get the guru's blessing LOL

Keep the ideas coming guys

Thanks Peppie

 

[mojoreef]

Yea I am still thinking on this. You should do some simple testing on the slot cutting idea in the tube?? Maybe grab a big plastic pop bottle and cut some slots into it, then a hole for water to come out on the bottom. This way you can half submerge the bottle and use your thumb or something to try and control the water level?? Tis way you can confirm that you can have the water level below/above or at the cut out slots.


Mojo

 

[TheKraken]

I will need to see another draft as I see the foam bubbles exiting from the inlet slits at the moment. Is this for inside the tank or a sump?

I see what you are doing as an air driven standpipe is a really elegant way to move water. It just looks like the intake at the top with the upward flow of the air bubbles will be fighting each other in this draft.

It looks like your design would make a great alternative to a bubble trap with sponge section in a sump. (is the water cascades over a baffle onto a sponge and then exits through a slit at the next baffle.) The flow rate is exactly the flow through of the sump and the exit level is controlled or tuned by a float switch... Let me find an image.

http://www.reefsanctuary.com/photopost/data/508/medium/Sump_New.jpg

 

[mojoreef]

Kraken this one is a little tougher then that. Its part of an in tank "All in One" drop in box. The problem with it, is that it is really small, something like 6 x 6. The teeth were their to take water into the skimmer, which is why I was asking for the test to see if we can even get past that part first.


Mojo

 

[Sasquatch]

Peppie? is the ladder thing sealed off like a wedge? if so you just reduced the volume by 1/2? what about 3 or 4 baffle plates instead?

 

[Peppie]

Sas, Yes the ladder is sealed off. I will make the wedges and weld them to the sides of the box. I realize that the volume is reduced, but I am shooting for more dwell time in the ladder/chamber. I thought about just using baffle plates, but if I angle it to let the bubbles travel up then it would not let all the water flow to the bottom. If they were angled the other way the bubbles would get trapped. That is why I went with wedges. I am going to do a test tomorrow, as Mojo suggested to see if I can get the water level in the mixing chamber to level out just at the top of the slits.

 

[TJL]

Hey Dave, here is another completely dif idea: How about having two or three Euro-style brace baffles a couple inches apart on walls of mixing chamber ??? Wouldn't this help to keep incoming water from bypassing bubble column down outside edges ??? Each baffle section would push water into center of chamber to mix it up. I bet that just a 1/2" wrap around baffle would cut the mustard for ya...


Cheers, Todd

 

[Peppie]

I could also feed this skimmer directly from a coast to coast weir. I would just need to attach a bulkhead to the backside of the weir so the water could pass thru the chamber wall and plumb it into the skimmer with a 3/4'' pvc pipe.
Would that not get rid of the issue of bubbles trying go get out the slits??

Also will the adjustable acrylic plate at the "water out exit" be tune-able enough to regulate the water level in the mixing chamber?? Or should a gate valve be used?

 

[TheKraken]

I have a del tec with the adjustable water level plate and it does fine. The lower part is sealed and the upper part rides in a groove. Setting highwater mark is easier than controlling the xsection at the bottom.

Have you considered fabbing a round tube with a square base as a drop in airstone skimmer? This used to be really popular. My deltec is a riff on the idea with a powerhead at the bottom of the tube with a exhaust hole at the bottom.

The baffels and wedges just look like an oppertunity for small bubbles (the good kind with high surface area) to become big bubbles and cascade up the ladder and burp at the collection neck.

 

[Peppie]

Kraken, Great point about the bubbles getting bigger. That would defeat the whole purpose here. have given the round on square idea some thought but I was trying to get as much dwell time as possible. Maybe I am over thinking that issue.

Todd that sounds like a great idea. Maybe start with a a thinner rim at the top and work my way down with a larger rim for every baffle. Or the other way around?? Cone shaped or -V- shaped?

 

[TheKraken]

a nice feature of the airstone is that the flow rate (and by extension, dwell) is independent. If you have a no bypass design you are filtering the effective rate of the return pump.

I will try to better discribe the idea and maybe make a sketch.