DIY Protein skimmer

[Guest cbo]

After reviewing plans for a protein skimmer on Sasala's a.k.a pez's web site, it just does not look that difficult.  I am looking for comments, maybe from pez, on the performance of the homemade skimmers, and maybe any recomended improvements to the one described on www.sasala.com. I am interested in this for a 20H with 20 gallon refugium I am setting up.  I have a six gallon nano now with no skimming.  I am interested in skimming but want to minizimze the damage to live things in the water, so I believe counter current is for me.  If I dont do this I will probably buy a CPR bak pak or some such.  Does anyone have any opinions/advice they would like to share.

 

Thanks

 

cbo

[Coral Hind]

CBO,

I have 2 clear acrylic tubes that are 3/16" thick, 5" dia and 9" long.  You can have if you need them.

[michaelg]

Years ago, before meeting Tom, I used his and someone else's designs to make my first skimmer (made from parts 90% of which were scored dumpster diving at construction sites- man what a poor grad student will do).  It worked like a charm.  For a tank that size, it should not need to be monster sized either.  The one I made was all from PVC except the riser neck that I made adjustable with an O-ring and a clear tube from a gravel vac.  Overall, the main chamber was 3 Ft high, with 4"PVC.  Weighed a ton.  I put ball valves on the input and output to regulate the height of water, and ran 2 air pumps (a tetra luft and a normal one).  The base was easy with PVC, though I attached it to a small piece of plywood to give it less chance of getting nocked over.  Are you going to make a sump for the tank?  This will impact the design a bit.

[Guest cbo]

The setup I am planning is on a 5 shelf gorilla rack in the basement.  On a middle shelf will be the 20H main tank lit by the 20k ushio 150W HQI from prevyet, see HQI DIY thread, and maybe a 55pc as well.  Then I will do one of two things.

 

Option 1

20L sump/refugium below fed by overflow from 20H.  With skimmer and return pump on sump then pumped back to main tank.

 

Option 2

10 Gallon sump below fed by overflow from 20H, pumped to a 20L refugium above main tank which then gravity feeds back to 20H main.  The idea being that the gravity overflow from the refugium is more gentle thank being pumped from refugium below tank.  So either way I will have a sump of some kind for skimmer, heaters etc...  The 20L is drilled about 2" off the bottom of the tank.  The refugium will be lit by a 4' shoplight at first.

 

So I would like to build a skimmer around 2' in height, but 30" would not be out of the question.  I am also interested in the skimmer that paul has in the F/S section but it is a venturi skimmer and is a liitle bit more than I can afford right now.  I am  also trying to build as natural a system as possible and the counter current seems to be the most gentle.  My only experiance with reef/marine tanks is the 6 gallon nano I setup in feb. and it has run fine with no skimmer, so that is one of the things which is leading me to gentle skimming.

 

Now prevyet has offered me these nice pieces of acrylic, pretty soon I will have to start refering to the tank as prevyet's tank at my house (he has given/offered so much of the equipment for it), can anyone suggest a design utilizing those shorter lengths, other than a venturi/downdraft.

 

 

Thanks,

 

cbo

[pez]

I most important thing about an airdriven skimmer is controlling the bubble size and quality of the foam.  Using a good airstone and a powerful air pump will give you good bubble size and duration.  The biggest problem I found with the design is my neck as too short, so I had a hard time controlling the quality of the foam.  I had to throttle the air pump back to get good foam, but that affected the overall efficiency of the skimmer by reducing the number of bubbles.  

 

I recommend some of the following

1) Make the neck longer (which is what I did)

2) Make the skimmer taller (36" instead of 30" should work)

3) Make the skimmer wider (4" inner diameter maybe)

 

All of these will give you more contact time and better foam control.  

 

You can even add two airstones for more bubble production, but then the skimmer has to be pretty tall to accomodate the extra volume.

 

Finally, the base needs to be much larger to keep the thing from toppling over.  I attached a piece of wood to mine, which might not be a bad solution anyway.

 

Just remember there is little science here; just build it and see how it works

 

 

-T

[michaelg]

The mod I appreciated the most was in making the riser neck of mine clear and adjustable.  I used a 2x 4">2" adapter to make the transition, and an O ring to fit the neck water tight but adjustable.  I lucked out in that the Lee's gravel vac tube fit perfectly.  I had it go up high into the top adapter piece to make for the overflow. In the end, I used 2 pumps, with 3 wooden air diffusers running full open.  I chose 4" tubing as the parts were easy to come by....  I originally tried using the venturi attachment on the powerhead to feed it, but could never get to pull air.  Not sure why, but this would have injected even more air into the chamber.  I angled the input pipe as well to try to give an tangential swirl.  

 

Michael

[Larry Grenier]

Hey cbo, on a side note I'd suggest Option 1 over Option 2... I know that that wasn't your question.  make a portion of the 20L a refugium.  Most of the fauna you want pumped from the refugium is larval or tiny anyway so they pass through the pump relatively unmolested.  I've seen surprizingly large pods and shrimp larvae pass-through a pump and look fine at the other end.  I'm just suggesting to KISS.

[Guest cbo]

Thanks for the input everyone, I was in TRT yesterday and they had a used D&D marine "the beast" skimmer for $10 so I bought it.  It needs a replacement venturi but that is all.  D & D will compleletly renovate it with a new venturi for, I am still waiting for the exact price, ~$40, so that might be the way I go.  I will probably start a new thread with more questions about my setup as it develops.  Thanks for your advice prevyet on getting the skimmer.

 

Michael and pez, are you both still running your homemade skimmers or have you switched to something else?

 

cbo

[michaelg]

I sold my skimmer with the tank I had in Houston before moving here.  I am using an aqua-C ev90 now.