Couple more questions about sand filter maintenance

[aquarium]

There's a 1/2" PVC drain pipe at the bottom that is capped. Do sand filters ever 'need' to be drained as part of regular maintenance? I don't want to put a wrench on it if I don't have to because it looks like something that will break.

The filter has been out in the hot Texas sun for at least 10 years, and the paint has faded back to expose the raw fiberglass strand wrapping. What type of paint is best to recoat?

Thanks,

TW

[Poconos]

Can't answer the paint question but the drain plug is just used for that purpose, draining the thing when necessary which is not part of routine maintenance. In the cold climates the filter does have to be drained as part of the winterizing process.
Al

[matt4x4]

yes, draining is only required when replacing the sand, or repairing broken laterals or winter storage.
As for what to paint it with, I don't know what the thing is made from, but you seem to point to fiberglass.
The gelcoat has worn off, so the best way to fix that is to replace the gelcoat
You can also use tremclad on fiberglass, but it takes MANY coats to bury those exposed fibers, you may be better off getting some marine Gelcoat - it will be a bit more, but probably worth it, painting that over the exposed fiberglass, a couple of coats of that should smooth it again, then just cover it with a paint for fiberglass.
Some automotive suppliers will actually tint your gelcoat so you could do this with only gelcoat tinted the color you want.
My buddy did this with a jetski that had seen better days, it turned out awesome.