I recently built a large sump for my mixed reef tank in my science classroom. I have a CPR CS100 overflow, 1" spa flex lines, and a reef run 5500 return pump. The overflow/sump input has a ball valve (soon to be replaced by a gate valve). The return line has a check valve just above the pump. See the schematic and images below. I cannot get a consistent flow rate through my system. The water level in the return chamber is constantly changing. Originally I was getting a lot of air through the overflow. I closed the ball valve a little bit and was able to get a consistent water level in the overflow chamber and stopped the air slurping. I have been adjusting the return pump power to try to match the flow rate of the overflow and the return. I can get the system relatively stable and it will stay there most of the day, but still varies around 1/2". Then, overnight the return chamber level drops significantly for no apparent reason. I suspect the outflow through the overflow is inconsistent. But, I am not sure how to get it to stabilize and stay there. This makes my ATO system useless. I am having a lot of trouble figuring this out. If you have any suggestions, I would really appreciate it! My next step is to shorten the overflow line to make a more direct travel path from the overflow to the sump. But, there is an electrical outlet in the pathway. I don't want the overflow hose to be above the outlet in case of leaks.
Can't get flow dialed in!???
- Thread starter SutterM78
- Start date
Coral reefer
Past President
Ideally the drain should. It go down then back up. In your pic it looks like it does?
Coral reefer
Past President
I would run it behind the tank so it maintained a downward slip the whole run
Coral reefer
Past President
Or put it on the end closer to the sump maybe? How many drain holes does the overflow box have? Just one?
Single 1” drain
It does. I was trying to avoid going above the electrical outlet
I think thats causing your issue. If it's a single piece of flex it should it shouldn't leak. What's stopping your tank that is also above that outlet from leaking?
If the tank overflowed in that back corner, it would contact the outlets. The return line is toward the front, about 18” away from the outlet. If a fitting started leaking, it would drip on the floor instead of on the outlet box. If I relocated the spa flex from the overflow to the most direct pathway, it would pass right over the top of the outlet box. Any fittings leaking would run down the hose and into the outlet.
Coral reefer
Past President
Ok, let’s get you a new glass tank and drill it for. Real overflow box. Problem solved. I bet you can get a 75 from petco for less than $100 and I’ll drill it for you.
Maybe people in here could even pitch in $5-10 each to make it happen for the sake of the kids.
I don’t like hang on backs to start with, and ones with one drain line are even worse imo
Maybe people in here could even pitch in $5-10 each to make it happen for the sake of the kids.
I don’t like hang on backs to start with, and ones with one drain line are even worse imo
Kensington Reefer
Supporting Member
ret pump flow is fixed rate
the line from cpr to sump has “u” in it
meaning the water flows down and then back up to enter the sump
shorten the drain line to remove the “u”
problem should be solved
the line from cpr to sump has “u” in it
meaning the water flows down and then back up to enter the sump
shorten the drain line to remove the “u”
problem should be solved
Kensington Reefer
Supporting Member
Also…
if stay with the cpr overflow box
i recommend using a power head with a Venturi nozzle to pull out any trapped air
if stay with the cpr overflow box
i recommend using a power head with a Venturi nozzle to pull out any trapped air
So, it appears my tank is mixmatched glass. The side panel closest to the sump is NOT tempered glass, if I am doing the test right. I compared it to what I saw looking through my glasses which I KNOW are tempered, and another glass panel that I use as a top that is also tempered. The LCD screen when viewed with polarized glasses through the right side of the aquarium blacks out entirely and evenly. When I looked through the tempered top, there was a lot of black, but light lines throughout. Looking through my glasses it did not black out at all. If you can recommend a good overflow and are willing to help drill the side, I would be grateful! My school is in the Santa Cruz Mountains. I can compensate for fuel if you are willing to come help
I have an Aqualifter pump attached to remove air from the siphon
I'm going to alter the drain line this week to take the most direct path. I'll put some heavy plastic over the electrical box for safety. Discovered that the glass closest to the sump is not tempered. So, I think I will order a different overflow and get some help drilling/installing. Thank you all for the feedback! This is my first sump build. I've been running HOB equipment for years. But, I want to keep some more particular corals for my students.
Coral reefer
Past President
Yes let’s do this. It’s not that weird to have some panels tempered and some not. I think they just use what they have on hand that is the right size sometimes.
I forget which brand box I got recently from aquatic collection, but I liked it. Might have been eshopps? There are some options out there, especially if you have time to order online.
I really prefer the “external box” type with either 2 or 3 drain holes so you can minimize the in tank part of the box and keep the drain really quiet and have a lot of flow through it pretty safely (as far as pumping saltwater through glass boxes near electricity indoors goes lol)
The hardest part would be to drain the tank part way. I prefer to drill when empty and the drill can be facing downward, but I’ve done tanks just like this would be without fully draining before just fine
I believe in you!!!
Coral reefer
Past President
That makes one of us!
Kensington Reefer
Supporting Member
There is no try...just do
The force will be with you
And, you’ve done it before
Or was it the Schwartz?
The force will be with you
And, you’ve done it before
Or was it the Schwartz?
I love Yogurt! Especially with strawberries!