DIY Recirculating skimmer - suggestions wanted

[Reef55]

I am going to build a RC skimmer fed off my drain. It will be an external (not in sump) in my basement, so I have plenty of room.

Total system volume = 300 gallons (125 gallon display, 150 gallon refugium, 25 gallon sump).

I am looking at either doing an 8" or 12" diameter chamber, and can go up to 4 feet tall for the main reaction chamber.

I am looking at using either the Gen-X 4100 or 6000 recirculating skimmers for it.

1) Which reaction chamber size do you recommend, and how tall?

2) Based upon answer #1, which pumps and how many of them would you run?

Thanks!

Mark

 

[Reef55]

No advice?

 

[Waylander]

Bigger is better. Taller is better. It becomes a matter of how much damage you want to do to the checkbook. Given your loose discription, I assume that you want needlewheels (and here I am - a beckett fan).

If it were me (within your parameters), I would go with the 10" or 12" at least 36" high for the reaction chamber. 2 Oceanrunner 3700 or Sedra 9000 would put enough air through it (preference to the ORs) and 3 would put you into serious overskimming if you so desired.

JMHO, of course.

 

[formula831]

Be careful with the height of the body...as I've found out that most pumps don't work that well with the added pressure (they don't inject as much air)...go with a 8" dia. or bigger...it's better to go bigger around then taller for the body!!!

 

[Reef55]

That is one of my questions... I plan on using 3 Genx 6000 pumps. I could do a 12" diameter, 3 foot tall chamber, or a 4 foot tall 8" diameter. Any thoughts on which way to go?

 

[fppf]

You mean something like this?

I would not go with a needle wheel pump. I tried a few versions with my mag 7's but they really don't have the power to over come the high head pressures. In the end I went with Mag 7's and the KEnt 3/4" venturi. Works very good, everyone that visits always comments on how clear my water is.

 

[Waylander]

Given parameters of 4' of 8" or 3' of 12", you will come up with a useful volume of 10.47 gallons with the 8" or 17.67 gallons witht the 12". The larger volume will be much less turbulent (read effective) than the smaller one. JMHO, of course.

 

[bededog]

Waylander,

Excuse my ignorance, but I don't understand which one is better from your explanation. Is more volume and less turbulence better or is more turbulence better.

Thanks.

 

[Reef55]

Fppf,
Nice looking skimmer Something along those lines, yes. Do you have any more pics or details??

Waylander,

thank you for the math. Sounds like the 12" is better... of course a 48" tall 12" diameter would be even better... 23.56 gallons!!

Bededog,

from what I have read, the less turbulance the better. That is one of the reasons why Bubble Kings are so effective... the diffusor plate at the bottom drastically reduces turbulence in the main chamber.

 

[fppf]

Thats all the pics I have currently, but feel free to ask for whatever and I can take some more. I'm not real good at just giving info, but I can answer directed questions.

 

[mattboy]

Quick question; for a 22-24" tall 6" diameter reaction tube, what would be a good pump for a recirculating skimmer; I'm looking to build one this size. Thinking of ocean runner 2700, sedra 3500, or GenX 4100. Any thoughts? It's for a 75 gallon corner tank I'm setting up.

Thanks!

 

[fppf]

From what I have read its all about bubble size and contact time.
Most skimmer mfgrs shoot for 1-2 minutes contact time, which is how long the water stays in the bubbles for. Bubble size is a product of how you make them. So once you pick a diameter and height you can then calculate how much flow you can have to get the wanted contact time.

 

[mattboy]

Sure, but in a recirculating skimmer the contact time is determined by flow-through, which is achieved by either a different pump or gavity feed from the tank overflow, and regulated by a valve. The question I have is, given this size chamber, actually 5.5" inside diameter (I use 1/4" wall tube; the 1/8" is not much cheaper at mcmaster carr and not as strong) by 22-24" tall, what recirculating pump would be appropriate? I'm kind of guessing, just using commercially available skimmers (turbofloter, ASM, euroreef) as sort of a guide.

 

[fppf]

The size of recirc pump will depend on how much air you want to put into the skimmer and how you do it. I did what your looking at, see what everyone else does and make a good guess. Worked out fine.

 

[GROSSR]

I am in the same boat. I am doing a 6"body about 18-20". My neck will be 3". I was told 2 OR 2700 or 1 OR 3700. I got 36" of 6" extruded for $24.00. I will tell you my source after I finish buying all my compenents.

rich

 

[mattboy]

Some progress; I bought a sedra 5000, and am planning on a 6" tube about 16" tall, plus a small box underneath, and a 3.5" diameter neck, probably about 6-7" long including what's inside the collection cup. From what I can tell, the sedra 5000 might be a little big for this size; euroreef seems to have 2 similiarly sized skimmers, one with the 3500, one with the 5000. We'll see.

 

[GROSSR]

I am going with the 3" neck. I going to put in a few inches of the neck and attach the rest of the neck with a rubber flex connector. I will start with a total of about 12" (total neck length) and start to adjust downward. I will use white PVC for this test and see what happens. Once I get a great neck length, I will cut the clear PVC the same length and glue it in.

rich

 

[jay-cee123]

<a href=showthread.php?s=&postid=6675216#post6675216 target=_blank>Originally posted</a> by GROSSR
I am in the same boat. I am doing a 6"body about 18-20". My neck will be 3". I was told 2 OR 2700 or 1 OR 3700. I got 36" of 6" extruded for $24.00. I will tell you my source after I finish buying all my compenents.

rich

Let us know where you got the 36" X 6" extruded for $24.

That seems like a pretty good price.

 

[shelburn61]

For taller skimmers you can overcome the head pressure problem w/ needlewheel pumps by putting the recirculating inlet on the bottom with the pump outlet a few feet above. Direct the flow down into the skimmer body and you will get just as much air and more contact time.

 

[GROSSR]

You can get 6" black ABS for 14.00 at Lowes.

Would it matter on a 20" tall skimmer?

rich