Has Anyone Enlarged Slots on Overflow?

[Jon]

I've got a 75gal Oceanic RR and just replumbed for increased flow and now have a problem. The flow has increased the overall water height so that it covers the bottom of the center cross brace thus preventing surface skimming on the right side of the tank and now I get a lot of scum build up.

The only solution I see other then reducing the flow is to enlarge the overflow slots. Has anyone actually done this and have they had any problems or suggestions. My concerns are opening them too much that fish or others fall over. When/If I enlarge the slots what does everyone recommend enlarging width or height. BTW, I contacted Oceanic and they say that would be my only option, but no other suggestions and they also said that they never heard of anyone else doing it. Thanks,

Jon.....................

 

[Anonymous]

I have enlarged the slots on all my store bought overflows with a dremel tool to increase the flow rate of the overflow.

It works great!

Of course, if you make them too big, some things might go over.... I guess You have to size them to your needs...

 

[Cory]

If you have a slotted over flow box you can knock out every other piece. You may want to use a black mesh or filter floss to cover the opening. I've opened up the over flow this way but I am not using a screen or anything. Fish are larger, and tank consist mainly of sps, some snails but have not lost any because of that.

 

[livingstone]

I have no water in my tank (120 gallon AGA) quite yet but I also expect to have to enlarge the slots in my overflows. I have purchased some plastic gutter guard mesh that someone suggested as a cover for the larger slots but I wish I could be sure that it wasn't going to leach any unwanted chemicals into my water. Does anyone know that this is safe or know of a for certain leach-free material to use? Someone else suggested craft mesh but I couldn't find any that was as course as I wanted.

 

[Zerj]

I have a 90 Gallon AGA and recently needed to enlarge the slots. I am using a MAG 12 as a return pump with a gate valve. Well I was patiently enlarging all the slots with an exacto knife (The tank was already filled) and had it to the point where I could keep the return 3/4 of the way open when a friend of mine came over and asked "Why don't you just remove the rubber strip behind the overflow?"

Oops I didn't even know that was there. Removing that solved my problem.

Zerj

 

[fnj]

I have a 125g AGA tank and I too removed every other slot and the rubber strip. I'm able to keep both of my reutrn pumps running full out, but the water is still a little high. So, I'm acutally considering removing all of the slots and using the gutter guard to protect fish from going into the overflow. You shouldn't have any problems doing this.

 

[M.E.Milz]

The AGA are easy to fix with a standard drill and bit. You can even do this with water in the tank, so long as you keep the drill out of the water.

The Oceanic tanks are a bit trickier because they use a thicker, more plexi-glass like material. I would suggest using a bit designed to cut acrylic.

FYI, in my Oceanic 200, I found that the size of the drainage bulkheads was the limiting factor of flow rate.