I'm going INSANE!!

[rocket]

Ok so I finally got all my stuff for a sump and installed it today, thanks to those that helped! But here is the problem. I cant leave the stupid thing for fear its gonna over flow the tank. I cant seem to regulate the water level, its either to high or to low. NO in between. I turn up the return pump every so slightly then it pumps the water level to high in the tank, so i turn ever so slightly (1/32" to 1/64" turn of ball valve) and the tank level drops and starts sucking air through the over flow.
Heres the setup, 75 gallon main tank, No-name CPR style over flow with a 1" bulk head rated 600gph?, 20g sump, mag 9.5 return pump y'ed into two 3/4" lock line flare nozzles.
Things were working but super noisy so I fashioned a "durso" type riser in the overflow (1" PVC, 1" T, 1" cap, but to make it fit I had to use a 3/4" 90 which slipped into the 1" T) could that be the problem? If so I have to hack apart a 1" T and a 1" 90 then re-glue so it will fit in the overflow box.
Has anyone had similar issues? What can I do to fix it?
Nate

 

[loohunter]

maybe you can replace the ballvalve with a gate valve they are way more presice than aball valve

 

[IAP Brian]

I don't have the specific science on the reduction in flow but, the Durso does cut some flow. The 3/4" 90 also cuts some more. Have you tried taking out the durso and putting a lid over the overflow box? that may quiet things down enough without cutting down on flow. There are also two other styles of drain mufflers out there that don't take up as much space as a durso and work pretty much as well. The stockman silencer works well, here is a link.
http://home.nc.rr.com/stockmanreef/interest.htm

 

[fly guy]

Sounds like the siphon isnt working super well if its fluctuating, and even if it was, the oveflow simply isnt really big enough for the flow you are trying to put to it. How are you evacuating air out of the siphon?? Are you uisng an aqualifter pump or venturi hook up to do this??

When talking about things like overflows that can potentially flood your floor if they fail you should always be way oversized and or redundant on set up.

I would suggest opening up that 1" hole in the overflow to 1.5" or 1.25 if 1.5 wont fit. With how thin some HOB overflows are made it may be a good idea to slap another 1/4" piece of acrylic on the bottom of it using weld on and then drill through that for your 1.5" bulkhead hole. Doing ti that way will strengthen it so it wont potentially crack when drilling it as well as just make it easier to enlarge the bulkhead hole.

Just some thoughts

 

[burning2nd]

try replaceing the 9.5 with a mag 7

u shouldnt have 2 do any of this... something is wrong

 

[btuck]

CPR style over flow with a 1" bulk head rated 600gph?, 20g sump, mag 9.5 return pump y'ed into two 3/4" lock line flare nozzles.Nate

Maybe I'm just stating the obvious but you have a 600 gph overflow and a return pump that does 900 gph. I would either get a smaller return pump or a larger overflow.
On that note though if you turn your Mag down with a ball valve you shouldn't start sucking air because the return should match the pump as long as it's under 600 gph. Does the CPR use the aqualifter? Perhaps that's another overflow.

 

[CarlaW]

Cpr does use the aqualifter.
If you don't want to replace the return pump, put a "Y" with a ball/gate valve on the return line line and return the excess to the sump. My 80 is set up this way, has been for 6 years, and I don't have any problems.

 

[fly guy]

The cpr's can use either a venturi or an aqualifter.......when i used to use them i actually preferred the venturi hook up............

 

[rocket]

Thanks for the ideas, I forgot to mention that I do have an aqualifter removing any trapped air in the overflow.
I messed with it more last night and what I have running now is a 3/4" 90 just sitting lose in the bulkhead. That allows some of the water to flow around the fitting as well as through it. It works but is super noisy! I'm gonna try a "AquaSilencer" type stand pipe, if that doesn't work, i might try a different overflow. although the cs-90 is rated at 800 it has a 1" bulkhead, the same as mine, does the width dimension make that big of a difference?