overflow help

Okay here is my problem. I have a 33 long that I got for free. It had been used in a fish store, so it had already been drilled. unfortunately it was drilled at the top, yeah I know what a PITA! It has 2 - 1" holes out and 2 - 1/2 holes in.

My question is the anyway to loose the toilet flushing noise that happens every so often. Is there something I can make to allow for better flow? since I am using it as a frag tank I am not to concerned about looks just want to get rid of the flushing an sucking sounds.

Any Ideas out there? oh, and plating the existing holes and re-drilling it lower isn't and option, it's full up and has allot of coral in it.

 

I was shown a setup to change on the overflow plumbing for top mounted overflows

Basically take a PVC T and hook it to the bulkhead coming out of the overflow, cap off the top of the T facing the ceiling and drill a small hole in it to allow for some air flow, and I mean small, like 1/16th at biggest
Then plumb off the bottom of the T, should help atleast from what this guy was showing me and the tank seemed pretty quiet with that setup, I've also though about building little ramps inside the overflows so the water isn't falling as far and making as much noise but I've never tried it so maybe someone else has ideas on it

 

Just have what many call a east west overflow made ? Its a horizontal type rather then a vertical system does the same job Two Bulkheads where you have them will never keep the surface clean and clear .. I have seen more then a few try to do this.. Good luck

 

I got this from melev's site (if I recall correctly). I actually made it and use it. It cost about $3.18 with tax, and is worth its weight in sushi grade yellow-fin tuna.

I didn't even have to tweak it. The moment I added it to the system, I had total silence. I recommend it heartily.

 

any tips on how to make it a better system?

 

Depends on what you have to work with in this case he had two holes drilled in the top as most all LFS have . I build a overflow box to fit the area where the bulkheads are located that will force the top inch or two to be skimmed right off the waters surface that is where all the waste oils from food and fish collect .. But I like the horizontal looking overflows rather then these little boxes .. What I make looks like a vertical reef ready overflow that just goes in horizontally to correct this drilling screw up. In a nutshell these go from side to side at the top of the tank rather then from bottom to top on the ends of the tank.
As I mentioned with a drilled tank like this you have litle control of the water line height and I have never see a system with a few bulkheads stuck at the upper waterline to fully clean the waters surface always a oil slick and or dead areas ..