Drain reef ready overflow and NOT drain tank?? Doable?

AmatuerAuer · Dec 17, 2015

I'd like to replace my plumbing and bulkheads to account for an added frag tank and return pump.

My existing bulkhead leaks if you blink at it. Here is the question:

Can you empty the overflow portion of a reef ready tank without draining the entire tank??

I'd like to empty and wipe down the bottom of the overflow inside the tank so the new bulkhead is attached to a dry surface.

It's a 4x2x2 All Glass tank. I will be replacing with a schedule 80 bulkhead.

redfishbluefish · Dec 17, 2015

If I'm not mistaken, a schedule 80 (of the same size) requires a larger hole.

AmatuerAuer · Dec 17, 2015

It may, multiple sizes and non 80 as well.

Any thoughts on the viability assuming the hardware fits?

wpeterson · Dec 17, 2015

If you have a well built overflow that is completely sealed, you should be able to do this.

When I do water changes, I turn off my return pump - which causes water to drain to the level of the weir on my column overflow. Then I usually pull the drain and return line plumbing inside the overflow (to clean them out), which causes the water in the overflow to drain down to the level of my bulkheads. If your overflow is well built and sealed - it can stay dry or at a lower level than the tank water in this way (mine does).

You will want to be careful to have either your sump or a bucket prepared to catch water that does leak. It also may be difficult to get the last inch or so of water out, so expect some mess with the bulk head removal as your last step.

If you want to be careful, I would test this theory with your bulkheads fully connected to your cabinet/sump plumbing so that all the water drains into your sump. You can take off the plumbing above your bulkheads and drain the overflow and verify it does not leak water from the tank into the overflow. Your mileage may vary, this is based on my setup:

column style overflow on back wall of tank, with holes drilled in bottom
bulkheads on each drilled overflow hole, plumbed into drains/returns in my sump
press-fit duroso standpipe, emergency drain, and return line T piping - it's not glued in place inside the overflow (to allow maintenance)

AZDesertRat · Dec 17, 2015

Why does your bulkhead leak? I would fix that situation while you have the overflow section empty and clean, it shouldn't leak if it is the correct size and installed properly.
My overflow section is watertight when I drain it for cleaning and maintenance.

AmatuerAuer · Dec 18, 2015

AZ - It is a reef ready tank with a corner overflow. I replaced the plumbing system under the tank and in doing so the bulkhead loosened a bit I think. It slides relatively easily when adjusting and leads to a drip that self seals with salt creep within a day or so but not until I have messed with it for sometimes 30 mins while it drips sometimes vigorously (and stressed me out!!) The union under the return line is at a 45 degree angle and i think it is placing some odd stress on the bulkhead which accounts for the leak. In other words, the pressure of supporting the spa flex tubing and the torque from the tubing is causing the seal to shift in place. There is also some detritus build up in the bottom of the overflow which could account for an imperfect seal.

That bothers me a lot and I plan to fix it quickly but since I am adding a frag tank to the overall system I want to wait on draining it until I can replace the whole nine yards and be done with it. That will happen mid January. The new system will have a better support structure in place to hold the return line and take the pressure off the bulkhead.

When I do replace it, I will drain the tank as far as possible likely 1/4 of the way down to keep my SPS from being exposed. Then drain the overflow section. Draining the overflow is easier said than done because it is threaded and cant be popped out. Trying to unscrew it WILL cause a substantial leak which I can jerry rig with a catch to keep the water off my stand and flowing into my sump.

Once it has been drained I will pop off the return, wipe down and dry out the inside of the overflow and put in a new bulkhead which I will then attach to my new plumbing set up.

Thanks as always to the community,
AA

AmatuerAuer · Dec 18, 2015

Also, Red Fish is correct. A Schedule 80 does not fit the hole it is too big by about 2-3mm.

AZDesertRat · Dec 18, 2015

I would say if you could, relieve the stress on the bulkhead. If you clamp the pipe to your stand or support it in some way it will really help the bulkhead seal better without having to overtighten anything. If you have not already seen it, I have a Bulkhead Installation Tips sticky post here on R2R with a lot of good information that may help you.