Flow change

[pass1over]

#ed_op#DIV#ed_cl#Got the sump ho0ked up. Tuned the ball valve to math flow into and out of sump. My problem is, everytime i add fresh water to top off the system, it begins flowing more water out of the sump than its taking in. Making me re-adjust the flow on the ball valve.#ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl##ed_op#/DIV#ed_cl##ed_op#DIV#ed_cl#Anyone else have this problem or am I doing something wrong?#ed_op#BR#ed_cl##ed_op#/DIV#ed_cl#

[Whoyah]

#ed_op#DIV#ed_cl#Your return pump is moving more water out then your input pipe can supply. You either need to open up your input line more (if possible) or reduce your output. Instead of constricting the flow of the pump you may concern putting a shunt line back to the sump. That way you won't damage the pump.#ed_op#/DIV#ed_cl#

[pass1over]

But it ran perfectly balanced and fine for 3 days. I add fresh water and the the flow changes.

The ball valve is inline with the water thats going into the sump.

[davejnz]

When you add the fesh water to your sump,the water level increases,the head pressure on the pump decreases causing it to pump more water.Although restricting your sump return via a ball valve will work,your decreasing your flow rate.Your problem is with your overflow.If its a H.O.B. style overflow,you can add another u-tube to it.i would also change the plumbing from your overflow to 1" thinwall PVC if your using 3/4".If its a corner overflow(reef-ready)make sure you use 1.25" thinwall PVC for your standpipe then reduce it back down at the bulkhead drilled on the bottom.If these reccomendations still don't return enough water to keep up with the sump pump,cut extra slits/slots in your overflow.
BTW,When i first ran my Mag12 wide open,my corner overflow wouldn't keep up.I re-plumbed the standpipe with 1.25" PVC and cut extra slots on the top and i can now run it wide open(950gph thru a 1'bulkhead)
I would also consider using a float-valve in your sump for auto-top-off to keep the water level stable

[pass1over]

First of all, thankyou dave.
If instead of relying on gravity to siphon the water down to the sump for me. Would it work if I attached an exact same size pump to the sump entry thats on the sump exit? That way, the flow into and out of the sump would always be the same? Maybe im wrong.

I dont have a water source nearby to setup an automatic topoff, or I would definately set one up. Would just adding water slowly to teh sump (would probably have to be every day or so) to keep it within say, 1cm of a certain balanced level keep it flowing?

At my wits end here with this. First sump setup and its besting me atm.

[davejnz]

Not the best idea pumping water from the tank to the sump,let gravity work for you via the overflow.It would be extremely difficult to match the flow rates of the 2 pumps,and as pumps get dirty,the flow changes so there are too many variables to overcome.Not too mention the pumps impeller would likely cavitate from the air that goes thru the overflow plumbing.Are you using a hang on tank (H.O.T sometimes called H.O.B.)overflow?
BTW,I also don't have a nearby water source for auto-top-off.A 5 gallon bucket with tubing plumbed to the float-valve in sump is gravity fed.with your 55gal,youd probably only have to fill the 5gal bucket up every 5-7days.It's such a simple design and beats having to top-off every day.I use mine as a sort of kalk doser so i never have to worry about alk/cal/PH.A stable water level in the sump(really the skimmer chamber) is imperative for proper skimmer function

[pass1over]

It is a h.o.b. overflow. Can i build/buy a type of overflow that works better than these? If so, could you point me in the right direction maybe?

I would add a bucket of water in the stand, but the problem is, theres no more ro0m under the tank for another bucket of water, the sump pretty much takes up all of it. I might be able to fit a small bucket of water under there. Will have to take some measurements and chek out how you set up a float valve.

If not, I guess I am going to have to be the automatic topoff unit huh?

[davejnz]

first measure the bulkhead/plumbing on your current H.O.B overflow,my guess is that its 3/4".If so,buy a 1" bulkhead and remove the 3/4" one.Cut the hole larger to accomadate the new bulkhead.Re-plumb with 1" thinwall to the sump,the standpipe that rises up into the back overflow chamber should be as small as possible.The lower the standpipe,the faster the siphon.If this doesn't work,cut more slots in the inside chamber(skimmer box).
You dont need to buy one of those expensive auto-top-off units.Get creative with your top-off bucket.You could use a rectangular shaped(trash can for example)reservoir that you could fit behind the tank.I just leave mine next to the tank,but it is an eyesore that way.You could always build a small cabinet next to the tank to hide it,it could double as storage for your reef supplies too.

[pass1over]

Its an overflow box i made myself. and actually its 1 1/4 standpipe (with ball valve inline) down to sump. So the standpipe i should neck down to a smaller diameter pipe?

How does the auto topoff by way of a siphon setup work though?

This is my first sump setup, so its all a learning experience.
Thanks for all the help.

[davejnz]

just cut the standpipe as close to the bulkhead as possible,the lower it is in relation to the water level of your tank,the faster it will flow