new 240g plumbing question

[Nim Dibbley]

I recently bought a used 240g acrylic tank (8' x 2' x 2') and i am having issues with the holes that were drilled by the previous owner. There are 3 holes on the bottom of the tank across the center and two on one side. I am not sure how it was previously setup and i would prefer to do something along the same lines as i am uncomfortable sealing these holes and drilling new ones. (I think it might have been setup as a room-divider and possibly even had stand pipes coming up out of the bottom.)

Aside from hole placement, the real problem i am having is the holes are pretty small. I bought bulkheads for .5 inch pipe (because they were the smallest i could find,) but those are too big to fit. The bulkheads say they need a hole that is 1.06" to fit and my holes are measuring just over an inch.

The holes are also threaded. Until today I thought that was normal.

The tank came with a wet/dry filter and the mechanical and chemical filter from this series: http://www.marinedepot.com/filters_pentair_aquatics_rainbow-lifegard_inline-ap.html

It also came with 3 submersible pumps and one external pump. All 4 pumps are pretty weak compared to the appropriate gph turn over rate suggested for a 240g tank. But if I used the two bigger ones that would be rated for about 1000gph, so I would like to use both for this setup.

To fix the problem, I tried to sand out one of the holes to see if I could get the bulkhead through and I spent about an hour on it. So far, the hole is still too small and I am covered in acrylic dust...

How should I proceed?
Should I continue sanding to make the holes bigger?
Should I buy a hole saw to make the holes a little bigger?
Do I have to seal all the holes and make new ones for bigger piping?

I have never drilled holes and i am not at all confident doing it. I also don't really want to spend any more money on this project so I really don't want to drill new holes....

Any answers are appreciated. thank you.

 

[vila_82]

The mechanical filters look great. as far as the acrylic drilling it should not be to hard. using either a hole saw or a regular drill bit... the trick is to keep the acrylic and the hole saw/drill bit cool so it can cut rather than melting. before you get to crazy drilling the holes bigger you may want to try matching the threads to some pvc threads. I recently set up a 210 gallon with two sumps... I ended up using the herbie silent overflow method which combines full siphon and overflow drain lines along with a spare (emergency) overlow. With all the holes in the bottom of your tank this setup might be easy to do. For examples of the Herbie style overflow type "silent overflow" in your browser. Good luck with your setup... be patient the end results will be well worth the frustration.

 

[Nim Dibbley]

thanks for the reply. I have tried to match the threads, but I cant find much that works. 3/4 inch piping is the right size, but I can't find bulkheads that would fit so I cant get anything going that would hold water in without dripping.

A uniseal might fit, but i don't want to buy and ship another product that might or might not work. And based on another thread I posted I don't think I should try and experiment with those on the bottom of my tank..