ER CS8-3, air and water flow- How much?

[A sea K]

In my never ending quest for a proper performing skimmer I have modded my CS 8-3 to a recirculating skimmer using the Eheim 1262 as the recirc pump and a Sedra 5000 as my feed pump.
According to the ER site the Eheim pulls 900lph of air and the sedra pulls 660lph for a total of 1560 lph of air and the throughput water flow of 500gph.
The skimmer has a 4.5" diameter neck and the total system volume is about 240 gallons.
Does this seem like it might be too much? When I first cranked it up it took a long time to stabilize and the water level is so low to keep it from overflowing that it is all the way down in the main body.
What would you do if this was your skimmer and setup to optimize the skimmer?
All input is greatly appreciated, Chris

[sjm817]

I would not use a NW for a feed pump. Just feed it ~ 1.5x system volume H2O only.

[A sea K]

That is how I set it up previously and was not happy with the result. It was working but very slow to pull skimmate, this is the same problem I have struggled with and cant find the solution for.
I know there is organics to skimm but everything I have tried has yet to give any satisfactory result.

[A sea K]

sjm817,
You know the history of my plight, and although the Eheim gave the best quality skimmate( drier and darker) it still didnt give much quantity. I had it fed with a MJ1200 at about 290gph, it would slow skimmate production almost to a stop after about 4 days, and at that point only make about 1 to 1.5 cups of skimmate. IMO this skimmer on this size tank should be producing way more than that.
Any reason not to feed it with a needlewheel pump? I set it up this way Sat and have been messing with the tank all day yesterday, cleaned and set the skimmer last night and it has made almost as much skimm overnight as it had in 4 days of the previous setup.

WHER ARE ALL THE SKIMMER GURU'S
CAN ANYONE HELP ME WITH THIS !@#$%^&* SKIMMER?

[sjm817]

If you put it together just like an RC250, it should perform the same. The RC250, H&S A200, Deltec 851 all use basically that same pump, have the same body size and all are great skimmers. You should be able to get very similar results. You should also be sure the outlet height is the same as an RC250.

[A sea K]

sjm817,
I used ER specs to mount the recirc pump. I had to mount it 3/8" higher than they recomended to use the original hole for the pump that came with the skimmer. I did not feel this difference in height would have much of an impact on performance but I have been wrong before.
When I questioned the location for the feed hole the ER tech said I could put it pretty much anywhere. I thought this was an odd reply. I mounted the feed inlet about 3" down from the top of the skimmer body.
The outlet is gate valve controlled and returns to a seperate chamber. How or can this effect the skimmers performance?
Back to your first post, Is there any reason not to feed it with a needlewheel pump?

[Reef Sponger]

Did you use the new ER Eheim NW pump or mod it yourself? If DIY, have you tried the mesh mod? If the recirc pump is working properly, no need to try to add more air into the chamber with a NW feed pump as that could cause more turbulence that is not desireable.

[sjm817]

The reason not to feed it with a NW pump is too much air for the body size. I still think you should put the outlet where ER, Deltec, and H&S put it. They all put it at that height for a reason. Its worth a shot.

[A sea K]

Reef Sponger, I'm using the ER modded pump and a little hesitant to mod it given the cost of a replacement impeller if it doesn't work out as planned. I don't have an air meter so cant be positive if the pump is operating at its penitential but feel it is. I mesh modded my Sedra9000 (non recirc) before going this route and feel they are about equal with possibly a slight edge to the Sedra especially in bubble size.
I thought the more air you could put in a skimmer the better but agree not the expense of turbulence, which by the way is an area of skimmer tunning I have yet to learn or properly identify.

smj817, This is exactly one of my questions, How much air is this body capable of without turbulence or other issues I don't know of?
Where does ER, Deltec, and H&S put their outlet? Inquiring minds want to know.

Thanks for the reply guys, if I can keep this thread going there might be others reply with additional info as well, and hopefully some valuable info to help me further understand the finer points of skimming.

[sjm817]

I would set your skimmer up to be as close as it can be to an RC250


Deltec 851


H&S A200

[A sea K]

smj817,
In my first configuration as a recirc using the MJ1200 as a feed, My output pipe matched closely to the examples you have shown(the tee location), however my valve is after the tee, not before it.
In an effort to maximize air draw for both the recirc and current Sedra5000 feed pump I raised the entire unit in the sump and the output tee is now lower by 4" than before.
One thing I don't understand about the output location: If you control the water level with the restriction from the gate valve, what impact could the location of the tee have other than the extreme too high or too low, resulting in obvious other problems?

[sjm817]

I dont think it matters where the gate valve is. You typically want the water level up near the top of the body where the neck starts. It seems "natural" to have the water output at the same level. I'm not sure though. It seem ER and Deltec have theirs lower than H&S.

[A sea K]

sjm817,I gave out and went to bed, sorry I missed your reply.
I looked over my situation and can raise the tee up if needed but it did not seem to benefit when I had that way previously. If I get home early enough I'll try to contact ER and see what they say.
I noticed that difference between the ER/Deltec and H&S as well.
One good thing to see was the feed pump inlet location, I am right in line with the others so that is good to know.

[sjm817]

Whats the latest? What are you using for a feed pump? Have you tried moving the T up to where a stock ER is? Can you post a pic of the skimmer setup?

[A sea K]

sjm817, I'm working with someone at this very moment trying to resolve my issues. Not much time right now but I'll send you a PM if its not too late when I finish up.