Plumbing help, DT overflows

[Plaz]

I would be nervous trying to break off the pumbling. In my experience, the bulkheads are the weakest fitting. From your more recent picture it looks like you could actually remove the bulkhead first and then unscrew the assembly from it. Is that the case? I think this would require draining just a little water from the tank in order to get the entire bulkhead above the water line and removing the bulkhead nut. I'm also basing this on the following...

To clarify; the assembly is not glued into the bulkhead but it can not be removed as the brace prevents a full turn.

[Plaz]

One problem with keeping the levels the same in both tanks is that the bulkheads are only really water tight on one side unless you've put another seal on the side that has the nut.

It sounds like what you want is essentially just an overflow from the DT to the mantis tank and fuge. If you leave the bulkheads up high and remove the inverted U then you've essentially got that, and it's just a matter of making the holes big enough or numerous enough to handle the flow into the DT. You could put an L into the bulkheads instead of the U in order to allow you to tweak the level in the DT a little.

[PEMfish]

With the BH wide open it still wouldn't flow through fast enough. I will have to add another,

[PEMfish]

So were all in agreement that another BH will do it?

[Jadinop]

This is just a thought but why not convert one of your returns installed in the display tank into another drain? You won't have to take much apart and no drilling. You can plumb another return up over the side if you feel that you need a second return installed. With the amount of flow you have one return should be plenty. If you run the water level slightly lower in the mantis tank it will still pull water through the bulkheads to keep the water in the mantis tank from stagnating.

[PEMfish]

The water level of the mantis will be the same as the DT as soon as I get the other BH. Each return is from a different pump, the right one is from the fuge on the right, the left from the sump. And I want the water to flow through the mantis tank. Also a pipe running over the top of the tank would have a negative affect on aesthetics. Plus the way the plumbing is done it really would not be optimal to drain from the return. Other than all that I do like that idea.

[PEMfish]

I got another BH and installed it next to the existing one. I was wide eyed and white knuckle wile drilling. I do not know if works or not ( as the cure to this problem ) as evaporation hasn't left me enough water to test the system. And now the salinity in the DT just went up. Soon as I make more water I will let yall know.

[PEMfish]

The 2nd BH is doing its job. But now I have another problem; the stand pipe and drain plumbing are not doing there job. I took the cap off but it sill wouldn't drain fast enough. It is most likely air in the line. There is a large cloud around the pipe in the sump, so that shows there is high volumes or air in the plumbing. Could it have been sucked down the stand pipe wile the cap was off? Yes. But there is still air in it. I will see what I can come up with here. Ideas are welcome.

[PEMfish]

If I put a T in the horizontal part ( hidden in pic behind return line ) and face the T up...

Then what? should I do a short length of pipe with a cap on it ( with a small hole in the cap )? Or seal some air line in the cap and let it hang? What do I do from the T? Is the T the best option?

[Plaz]

If you are pumping only 266GPH and your down plumbing is 1.25" PVC, then I don't see anything obvious that would explain why your standpipe isn't keeping up with the inflow. Nothing stuck in the drain tube? Maybe you have one of these holed up in there.

How far underwater does your drain line go in the sump under normal operation? It looks like it goes almost all the way to the bottom of the sump which I suppose might cause a little extra back-pressure, depending on how full your sump is.

The next thing I'd try is either replacing the 90 degree fittings with 45 degree ones or replacing the last 90 degree with a sideways T and an extra foot or more of uncapped pipe sticking straight up to allow some air to escape out the top.

[PEMfish]

I yanked the check valve out of the horizontal part and it works great. I GOT THIS FIXED!!! Now I just have the fuge and details to work out.

[Plaz]

Glad you got it working! Congrats!

I missed that your check valve was in the plumbing going to the sump. I've never heard of doing that. I've seen them after the pumps going back to the display to prevent backflow, but am not sure what the point would be in putting them on the drain side.

[PEMfish]

It is not a check valve in the plumbing, but a air check valve, to release air. I yanked it out and now it works. My new BH leaked a little, even all the way tightened, if I crank on it any more the whole thing spins. So I smeared some silicone around it on both sides and we will have to see.