Siphon Overflow ?

[NCFish]

I have a 600 GPH siphon overflow system. I am using an aqua lifter pump that allows it to keep its siphon. The water pump I am using is also 600 GPH. The problem is the h2o is dumping into the tank slightly faster than it is leaving. Damn thing overflowed once and almost another. The overflow box is only about 1/4 full of water at all times.

Any info would be greatly appreciated!

NC

[movinweight]

always make sure to have an overflow box that can handle more than your pump is pushing. Trying to match their gph will only lead to overflow. I use a CPR 100 overflow rated at 800gph but my return pump is only pushing 200-300 gph at 4' head height. Look into getting a smaller pump and add powerheads in tank for circulation. HTH

[NCFish]

What do you mean by 4' head height?

[movinweight]

This is the measurement in which the return pump has to go against gravity and push the water back up to the tank. Even if a pump is rated at 800gph max, that number lessens when you have to push water back up against gravity. From my return pump back into my tank is approximately four feet. Usually they will send a chart to show you the ratings at certain heights. I know that Mag drive pumps include this.

[movinweight]

what type of overflow are you using?

[Bill Z]

my pvc pipe overflow
http://thereeftank.com/forums/showthread.php?t=78117

[NCFish]

I am using a continuous siphon overflow w/ a 1" bulkhead.

[movinweight]

I still think your issue is the amount that the overflow can handle, very difficult to determine what the max flow could be unless you have a flow meter. I like the design though, coulda saved me $100 on my acrylic overflow box. The only disadvantage is that you really need to skim off of the top of the water to get the "slickness" out and provide good gas exchange. When I upgrade, going to have to get a "reef ready" tank with internal overflows or durso standpipes.

[outy]

a 1" bulkhead witha durso will handle your flow problems without it you are looking for trouble.

[bubblethumper]

You should just T-off your return line with a ball valve right back into the pump area. This will allow you to adjust the amount of flow being returned to the tank:

A) without buying a new pump
B) without drilling
C) at minimal cost

[movinweight]

but might burn the motor on the pump quicker!

[bubblethumper]

<a href=showthread.php?s=&postid=7776643#post7776643 target=_blank>Originally posted</a> by movinweight
but might burn the motor on the pump quicker! I really have to disagree.

If anything, the pump works less hard when part of the flow is being redirected right back into the sump (and not being forced through a ton of friction and head-loss inducing pipes).

The situation you are talking about (when the pump works harder) is when the intake to the pump is restricted with a ball valve