sump overfilled!

[alisa1965]

I have a 90 gallon saltwater tank. I recently had someone make me a sump. It is a 20 gallon long (30" long x 12.5" tall. As you see from the pics, it has 3 sections devided by 4 baffles. From left to rt, there is a high baffle extending from just below the black trim to the bottom followed by a shorter baffle, then the other section has the shorter baffle followed by the taller baffle. The right side is my skimmer and pipe (thru a sock) from the aquarium and the left side is the return. As you can see from the second pic, the return (950 gph) has just a little water in there, enough to cover the intake of the pump. I run a Bubble Magus NAC 3 skimmer.

I don't think these baffles are correct in size. My skimmer needs at least 8 inches of water to work correctly"¦in theory. When the sump is filled, it is completely full (just under the trim). My skimmer is completely filled to the neck and overflows the top whenever I turn it on. So, I had to lift it up and it seems ok now. Probably lifted it 4 inches up as you can see from the pic. The pipe coming from the aquarium is 1 inch. The water flows to a refugium in the second section. All I have in here is a rock, some macro and a sally lightfoot. The third section on the left is my return pump (3/4 inch pipe).

Once I shut off the pump, water fills the entire section. So, I am thinking, I need shorter baffles, correct? If so, what size is best for all walls? I was told to take the return pipes (the little black ones) and aim them high which might help. Nope. Still fills the sump. It isn't overfilling but that is way too much water. BTW, my return pump kept pulling in air. It has a smaller intake than the pipe running to the tank and to stop the sucking of air, I had to run a hose and aim it down. Also, I do have a water top off. Any help would be appreciated.

 

[oldbones]

I would recommend lower baffles, especially in chamber one, then you can run higher level in the return chamber and still have enough room to hold all system water with power off.

It's ok if the sump fills almost to the top with power off, as long as it doesn't overflow! However, be careful that any lines coming into the sump (dosers, ATO) don't end up under water with power off, they can siphon water from the sump back to your dosing or ATO reservoirs and cause a flood. (Happened to me, had to raise my hoses up to the top lip of the sump)

 

[alisa1965]

So what would be a good measurement of all the baffles?

 

[oldbones]

Well, I guess that depends.

How big is your DT? How much water does it drain to the sump when you shut off power? How big is your sump tank, and how much more surge volume do you need? How many baffles are currently in the sump, and do you need them all? Can you post a profile pic of the entire sump? If not, a decent semi-scale drawing would be good.

It's possible you could just cut down the existing baffles (in place) to achieve the same result. The cut wouldn't have to go all the way edge to edge.

 

[C3hutson]

Show us your return nozzle in your display tank. If you have that too low in there, what's happening when you shut off your pump is that a siphon is pulling water out of the DT through the return line. If this is the case, drill a couple small holes right under the water level in the return line so that the siphon breaks as soon as the water drops below your overflow.

 

[alisa1965]

here is a pic of the sump when full. Original post has all measurements

 

[alisa1965]

C3hutson There is a hole drilled in the large white section of pipe that goes from dt to sock to break the suction, not the return. It came this way when we purchased the tank. I was told to lift the black fan type pipe that is attached to the return that is in the DT but that doesn't help.

 

[billdogg]

The skimmer section baffle should be at the height required by your skimmer - mine is 9", and to make my life easier, the refugium section and return section are at the same height. I use a 40b for a sump, so that gives me ~20g in the sump (or 1/2 full) when the tank is running. That allows for more than enough space for backflow from the DT when the pumps are off.

 

[broke1]

C3hutson There is a hole drilled in the large white section of pipe that goes from dt to sock to break the suction, not the return. It came this way when we purchased the tank. I was told to lift the black fan type pipe that is attached to the return that is in the DT but that doesn't help.

That's not the pipe he is referring to, if it was you would have a beautiful sprinkler. The fan shaped one you mentioned above it is, it actually needs just a tiny hole, make sure it isn't pointing up.