POLL: Overflow Box....HOB or In Tank??

[runway1]

Do you prefer HOB or in-tank overflow boxes and why?

 

[sdellin]

Don't you have to have a pre-drilled tank for an in-tank overflow box?

 

[seaham358]

I like the drilled tanks, several of my friends have had the overflow box and they have failed and had floods. They can loose suction ater a power outage, when the power is turned back on the water pumps out of the sump and when the OF does not work the extra water goes on the floor.
Both my tanks are drilled on the back, upper corners and they have been running problem free.

 

[runway1]

Yes, sdellin, you do.

Seaham358, wouldn't you drill the bottom? Where exactly did you drill yours?

 

[schoeplein]

Some tanks are drilled on the back -- not the most efficient design IMO.

I had a HOB fuge. Worked ok. But if you've got a properly designed and pre-drilled tank with overflow then that of course is preferred. Which is what I switched to. 75g w HOB to 110g with intank overflow to drilled hole down to 30g wetdry/fuge. The HOB had an intank overflow box that siphoned out water with a big plastic tube. Worked pretty well but it was a pain in the butt to keep balanced to make effective use of the bioballs. Day-to-day balances

Weekly topoffs -

 

[seaham358]

runway, unless you get a tank drilled already(reef ready) then the bottom will more then likely be tempered glass, Termpered glass can not be drilled. Getting a predrilled tank can cost more the getting one not drilled and then installing your own holes. Most glass stores drill holes..
I have them about 3" down and 4" in in both upper corners.. I'll try and post a pic later. If you don't have a RR tank IMO this is the bast way to go..

Scho why are the tanks drilled on the back not efficient?? I belong to a club and there are a lot of members who have them set up like this with no problems. I get great flow out of 2, 1" bulk heads returns, I would say almost 1200 gph if I have the elbows adjusted for a fater flow back.
1" hole in bottom will have the same flow as a 1" hole in the back???
Would like to know what info you have that says these are not efficient..

 

[lando]

I prefer reef-ready tanks.

 

[schoeplein]

Seaham - to answer your question in one word: Gravity.

 

[AndyH5512]

I have had both, and both work very well. I prefer the pre-drilled tank, though. It fits closer to te wall. Also seems like the flow is better.

 

[sdellin]

Here's a question for y'all... Is there any mechanical fix to the problem with HOB overflow boxes in case of power failure? Like, maybe using a power source for the sump pump that does not automatically turn back on, maybe you have to start it when you get the syphon going again... or maybe some mechanical restart for the HOB?

I am planning a sump and had "non-pre-drilled" arcrylic tank. Someday I'll upgrade, so I really don't want to take everything out of this one and drill it.

 

[AndyH5512]

When I was using the HOB overflow, and there was a power failure, I never had a flood. The overflow will only take as much water as you have it adjusted to take. Once the power fails, and the tank water goes below the overflow's level no more water will flow to your sump. I recall thinking the same thing, so after I set mine up, I unplugged it to see what would happen. My sump came nowhere near overflowing. Sounds crazy, but its true.

 

[runway1]

Not crazy, that's the design and intent. Same with an inside overflow. Once the water level is below the "teeth" on the overflow box, of course, water flow stops.

 

[seaham358]

Scho, that tells me that you have no info on which is better its just your opinion.
If I had a choice I would get the bottom drilled, the issue may be you already have a tank and if you do 99% of the time the bottom is tempered so you can not drill it. So drilling the back is better then using a Overflow box.

Sdellin, my friend has a small power head in the OF box and has a hose attached to it in a fashion that it sucks any air that gets trapped in the overflow section of the box. That may help if it loses suction??

 

[Kam]

I am planning a sump and had "non-pre-drilled" arcrylic tank.

Unlike glass, Acrylic is very easy to drill.

 

[sdellin]

Thanks for the advice all, I was thinking of trying to set up some kind of pump in the OF box.

Who knows, I may end up drilling the back since it is acrylic, but I just hate to remove all the fish and water and I'm assuming I'd have to do that.

 

[seaham358]

if you were drilling the bottom yes... The back no... lower the level so its a few inches below your drilling area.. acrylic tank should drill easy.
My friend drilled his 125 glass tank half full and mad out well.

 

[pearsont74]

does anyone have a write up on building a overflow in the tank? i know the drilling part and the interesting thing is my tank is drilled - 2 holes
i didnt go this route cause I didnt know how to build the overflow inside the tank and ensure it works correctly
of course now changing will be a huge pain but it may be worthy to do before moving forward on stocking my tank

if anyone can send my links to info on this Id appreciate cause I would like to fully research this before considering the change