valves on drain lines?

[blueboy]

is it safe to put valves on the bottom of the drain lines coming from my overflows? i'd put them just above the sump. i'm just trying to cut down on the amount of air that the water pull down into the sump with it. i think this will help out with noise, and salt creep. obviously, if they were turned back too far, i'd have a flood, right?

[captexas]

Its good to have valves and unions in case you need to change your setup around (pump, sump, plumbing) or do some cleaning and don't want water draining down. As far as the noise and such, what kind of overflow are you using? If it's a decent design and it's running properly, you shouldn't have that much if any air. If it's a hang on overflow, there are a few things you can do such as putting a piece of foam or filter floss in the overflow box. Also, make sure you use some airline tubing and suck the air out of the U-tube. If it's a Durso standpipe type overflow, search the web and there are various modifications you can make to reduce noise and air.

[GaryP]

Short answer is no.

Long answer... Any restriction in the drain line is going to potentially cause a back up of water in the tank. The valve is just going to serve as a place for stuff to get daught in the line. If you are trying to cut back the amount of flow going to your sump, that's not the way to do it. Cutting back on the flow from the return pump is the way to do that. Either through downsizing the pump or diverting part of the flow to a refugium or something else. All it takes is a snail getting in there and you'll end up with a flood and a burned up return valve. There are better ways to go about what you are trying to do. I'll let the DIY plumbers jump in here and give you some suggestions on them.

[blueboy]

it's an oceanic RR, with dursos. i already have a piece of floss in one overflow to cut down on the spashing sound( one OF skims more than the other, the tank is level, i think it's the notches in the OF that aren't, there's a vivible difference in the amount of notch you see beneath the waterline)