Need some pluming help From the Pros…

[lexunit]

I’m cycling my first saltwater tank, I’m on week 3 of Cycling and I’m just now having some return pump issues. The return section of my sump is starving out real fast. It was running just fine before. I have a gate Valve on the return line. I’ve tried closing the valve a bit, it would be fine for a few days and then pump will starve again. I’ve tried adding more saltwater but problem returns. I’m beginning to think that there’s something wrong with my Overflow or pumping. I have a 40 G Breeder with Glass Holes.*** 700 gph overflow kit connected to 1 ½ “ pipes. From the bulkhead it goes to a 90 elbow with a vent tube, then straight down to 90 to the right to a T into the sump. I have a Quite One 3000 pump ( 819 gph). I was running the pump with the return valve wide open for 3 weeks with no issues before. I’ve check the vent tube for any blockage or salt creep, found none. Please Help. Here are some pics of my set up.

Thanks

[reefermad619]

I would start with replacing all 90s with 45s. With durso style drains, hard turns are very restrictive. Also get rid of the ball valve on the drain. Not to be mean, but its useless there. You should valve a durso. The valve on the return is all you need. Don't worry about breaking apart the plumbing. The union on the drain you have is all that's needed. Cut back the return to half. Then see how it runs. Move it up slowly til it balances out. You'll probably also have to play with the air tubing in the pipe as well. I would seriously consider switching to a bean drain or herbie drain. With those style of drains you're not limited by the drain as to how much flow you can run. You're limited my how much flow the return pump can produce.

[uncleof6]

So I would ask: where is the water going? If the water level in the return section is getting lower, the water level in the tank must be getting higher--unless the loss is due to evaporation. You did not mention the water level raising in the tank. (or overflow.) Excluding evaporation, it would have to be your drain line cannot keep up with the flow rate from the return pump. The disparity would have to be small, to take several days to notice it.

Couple of things with your drain line: You are running an air/water mix drain, and there is only one drain. It is not advised to have a valve in the drain line, as it causes a restriction (even wide open) in the line. Your drain line comes down to an elbow, goes horizontal, then hits another elbow, continues horizontal, to the tee, and then down. None of these features are good to have in a drain line, and the tee does basically nothing. The drain line should be kept at a downward angle, with as few fittings as possible--and no valve, for there is no purpose for it in an air/water mix drain. Changing these things will improve the performance of your drain, however, it is still an air/water mix drain (durso modification) and will cause problems if the flow rate is too high ~ < 350 gph, it does not really matter that glass-holes calls it a 700 gph overflow. Max for you size tank should be around 400 gph for the sump return anyway.

A block in the air tube would improve the performance of the drain, (less air = more water) by making it a siphon, rather than cause your return section water level to lower. However, due to the configuration of the drain, it may not go to siphon. (unable to purge the air)

I would rework the drain, and see what happens. Evaporation is the only other thing that would make any sense. (3 weeks without issues is noted)

*EDIT: don't see any reason to not have this right below 619, I type, walk away, come back, type and seldom refresh*