Large Air Pump

[dwall174]

I’m looking for a large air pump for a 6” x 5’ DIY skimmer! I remember reading a thread a while back where a E-Bay vendor had some refurbished linear pumps!

Does anyone have the web site?

If not any recommendations on a air pump large enough to handle a 5 foot skimmer?

[Geoff]

i assume you are just going to use airstones? i do not think you need as much of a monster airpump as you think. how many airstones where you hoping to use in the skimmer? i would find the pump that could handle that many stones at 5' of pressure.

G~

[dwall174]

I'm thinking of making a Snailman's style skimmer I'm figuring on running four 3" wooden air stones. The reactor chamber will be 6” x 5'. I have two Tetra DW-96-2 air pumps that are claimed to run three 1" air stones at 96"! They work ok with my smaller 3" x 36" skimmer that I run two 3” wooden air stones in! However I don't think they would keep up with the bigger skimmer?

I have two 1” drain lines coming from (back of tank) corner overflow of my main tank, I plan to use one of the 1” lines & a ball valve to control the flow to the skimmer. I have thought about trying to add a venturi & pump to the skimmer to cut down on the amount of air needed from an air pump? Has anyone tried to combine a venturi & counter current air skimmer?

[Geoff]

that is what Top Fathom skimmers are. they are a venturi driven counter current skimmer. Nikki has one on her system. i went with a triple pass in order to keep the height down. venturi's have thier advantages: less maintenance to keep efficient, greater number of places to put them. disadvantages are: not as efficient as air driven, larger pump needed to power the venturi valve.

if you are looking to use airstones of that size then i would have a look at www.aquaticeco.com. they have a lot of linear pumps to choose from.

something to ponder. Spanky like to have 3-4 times the volume of the system pass through the skimmer per hour.

i am in the process of trying to figure out how to do this with my skimmer. i think i will be getting a bigger venturi valve.

G~

[dwall174]

Originally posted by Geoff
if you are looking to use airstones of that size then i would have a look at www.aquaticeco.com. they have a lot of linear pumps to choose from. G~

Yea I know I got their fish room catlog Now just to figure out which one would be best?

something to ponder. Spanky likes to have 3-4 times the volume of the system pass through the skimmer per hour.

That's interesting because the information on Snailman’s web site recommends a lower flow to allow for longer contact time? I guess that's another thing to consider when trying to figure out what size air pump to get?

Here's a drawing of what I'm planing so far!

[dwall174]

And here's a pic of the back of my system where I plan to install the skimmer. There's also some more pic's in my gallery.

[Geoff]

Originally posted by dwall174
That's interesting because the information on Snailman’s web site recommends a lower flow to allow for longer contact time? I guess that's another thing to consider when trying to figure out what size air pump to get?

apparantly there are a lot of differences between the way we hobbiest do things and the way the aquaculturist do things! i tend to think the AC people know more.

with a 6" diameter skimmer flow out of the skimmer will not be a problem. you should still be able to keep a good contact time in the skimmer. BTW-did you know you do not want to have a dry brown foam but tea coloured skimmate?

what size drain are you thinking to go into the skimmer? i would think you do not want to go with anything less than 1.5" in order to keep the flow up.

with that many airstones, you should not have a problem removing organics.

how big is the total system?

G~

[dwall174]

Originally posted by Geoff
what size drain are you thinking to go into the skimmer? i would think you do not want to go with anything less than 1.5" in order to keep the flow up.
G~

Being that I plan on running it from the main tanks overflow which is a 1" bulkhead I figured on 1" to feed the skimmer & 1" or maybe 1-1/2" for the outlet? I'm also not sure on what style outlet to use. The loop style like Yours & Snailman's or just a gate valve like I have on my current skimmer? My flow through the main tank is around 900~1000 GPH through the two 1" bulkheads so if I split them I should get between 400~500 GPH through the skimmer.

how big is the total system?

The total system is around 140 gal right now However I want to upgrade the main tank this summer to a 120 gal. from the 65, I currently have. So the skimmer needs to be able to handle 200+ gallons.

It's funny how these simple little jobs turn out to me a major project!

[Geoff]

Originally posted by dwall174
It's funny how these simple little jobs turn out to me a major project!

you should see what my house looks like now.

the skimmer itself will handl just about anyflow you put into it. when building it i would put at least a 1.5" outlet on it. the gate valves are easier, but more finicky, that is why i went with the loop. gravity will always work.

for the inlet i would also put at 1.5" that way you have that much drain now with gravity. later on when you get the bigger tank you will prolly want to convert the inlet over to 1" or 3/4" and push the water through it using a pump. the greater the bio-load the more water you should blow through the skimmer.

G~

[adrianleewelch]

Just wanted to add something. My skimmer is 4 feet tall, and I bought a tetra tech deep water pump, they have several models, mine will do 1 four inch stone at 96 inches or 2 four inch stones at 48 inches, which is how I have it set up, I have a mag 7 powering it at half throttle, so approx 300 GPG through it, I have a total of 135 gallons with sump and fuge included, so just over 2x turnover rate, I use a gate valve on both sides of the skimmer and can tweak it without any probs. It can make 8 ounces of tar or a gallon of tea in a day, I run it wet to make me change a gallon of water daily !!!

[dwall174]

What type of pipe are you using? I'm still trying to figure out which size pipe to use?

After several trips back and forth to Lowe’s & Home Depot I just figured out that they have two different sizes of 6” PVC one is the schedule 40 & the other one is a lightweight version made just for drain lines. Those flexible reducers like Snailman used are made for the smaller OD drain line & of course the 6” PVC I just happen to have is the schedule 40!

FYI the schedule 40 is 6.625 OD & the lightweight drain PVC is 6.275!

Anyway tomorrow I’m going to check with a plumbing supply company that caries commercial supplies & see what they have? I could always go with the smaller OD pipe but I would like to be able to use the 6” that I have! I also have 6 feet of 4" PVC that I could use?

BTW my current skimmer is 3" dia. with a 32" reactor body that I run with one dual outlet tetra tech deep water pump & two 3" air stones with a hagan 402 PH. I call it a 3 foot skimmer but it's realy 42" counting the collection cup.

[adrianleewelch]

that skimmer looks almost just like mine, I used schedule 40 because you kinda have to use all 40 or all of the thinwall, they wont interface well enough to seal properly, according to the plumber I asked. I only use 1 inch intake and drain, but was aiming for slower flow and longer reaction time, dont necessarily think this is better, only what I had on hand. I am gonna build a duplicate and use bigger pvc and up the flow through it and see which one produces the best skimmate, oh yea those gravel vac tubes make great riser tubes and almost fit the 2 inch pvc perfectly, just had to use some epoxy and silicone in the small gap and it gives me a 8 inch window to look through to adjust the bubble column

[dwall174]

Originally posted by adrianleewelch
oh yea those gravel vac tubes make great riser tubes and almost fit the 2 inch pvc perfectly, just had to use some epoxy and silicone in the small gap

Yea I know that's what I used it was a small dia. tube that fit nice into the 1-1/2" fitting.

For the new 6" dia. skimmer I think I'm going to go with a 3-1/2" OD Acrylic riser tube. It’s the same size as the 3” PVC fittings & a local plastic shop will sell me just a foot so I don’t have to buy the whole piece.

[adrianleewelch]

I have not been able to find any acrylic in my area, but I live near dallas maby I could look there, what type of company might have acrylic in the same sizes as PVC, no one has been able to help me locate any, What kind of plastics shop do you mean ?? They all look at me like im crazy when I inquire about it.

[Geoff]

i also can not find any around here. or if i did they do not sell to the general public.

i usually just order it from www.aquaticeco.com. it is a bit more expensive than if you could get it directly from a supplier, but it is close. another place to look at is Tap Platics. they have several locations around the U.S.

hth,

G~