When I drilled the bulkhead in my sump I put it centered along the bottom of the sump. But now I have decided to add a refugium and to clear space under my stand, I need to move that bulkhead so it is aligned towards the right side of the sump.

How should I block or plug the hole I drilled for the bulkhead once I remove it? I used PVC glue to attach the PVC to the bulkhead, which is then attached to a Union, so I could reuse the bulkhead, but I need something small than a bulkhead to block that hole.

Also, I bought some flexible PVC (spa flex tubing) to replace PVC on my return line. I am planning on attaching it to some slip Unions and attaching those to my existing union connections. Can I use PVC glue on the spa flex tubing? I don't really feel comfortable with a slip fitting.

Thanks!

it would probably be best to buy a new bulkhead and just cap off the old one at the PVC that comes out of it.

you can use primer and cement on spa flex tubing. i have done it many times with no problems.

I was told there is a glue specifically for spa flex that works much better, but the primer is the same. I got mine at a pond store its blue and quite thick.

I would cap the old bulkhead and redrill.

I used regular PVC glue on my spaflex. Two years and no sign of failure yet...fingers crossed. I would have got the correct glue if I could have got it locally though.

I am assuming this is a glass tank. If it is glass, you could try to silicone a piece of glass over it but I can't speak to if having that hole without the bulkhead support would leave the tank bottom structurally weaker.

But if it were acrylic, it shouldn't be a big deal to weld a patch over the hole.

Thanks everyone. The sump is acrylic and I think the patch idea would be best. I want to free up the space left by the old bulkhead to put in a fuge and I can do that with a patch on the inside of the sump. Also, the guy at Lowe's said I couldn't use pvc glue on spa flex, and that didn't seem right to me so that's why I was checking with TR. Thanks for the confirmation!