got ethical husbandry?

overflow advice.

gigabyte

gigabyte

Guest
BARcard
I recently acquired a 75g tank from a friend. i want to install an internal overflow, but i am unsure of what size i actually need. i was planning on purchasing an overflow kit from glass-holes.com and i noticed that they have 2 sizes available, 700gph or 1500gph. this would be my first setup besides the all in one nano cube i have now. also if anyone knows of any places that could help me drill the overflow and return holes that would be great as well.

-steve
 
You likely only need the smaller, but you may want the larger.
My guess is you will run around 500gph through your sump for a tank that size.
But that assumes you run power-heads in the tank. If you want all flow to be
from return pump, you will definitely need the 1500.
Also, up-sizing can often make it run quieter, and give more margin of safety.
 
Bigge is better, don't have to run the max through it, more options that way tho. Like rygh said, likely to be quieter. A hole out the back with a 90 degree turn limits flow compared to a hole
In the bottom
 
cool. also where should i install this overflow? is it best to put it in the middle of the tank or off to the side? also where should i drill the holes for the returns?

thanks
 
gigabyte said:
cool. also where should i install this overflow? is it best to put it in the middle of the tank or off to the side? also where should i drill the holes for the returns?

thanks
Click to expand...

Most people put overflows in corner. Less visible/ugly there.
Although center is probably more efficient as far as skimming surface crud.

The actual return nozzle needs to be near the surface, so you do not get
a major siphon when you turn the pump off.
As such, drill holes near the top, probably on the ends not back.
Alternately, returns can come over the top, so you don't have to drill a hole at all.
A neat alternative is to run the return up inside the overflow, so less visible. But a pain.
 
I wouldn't worry about functionality of where the overflow goes, middle
Probably a little better, corner is fine as wellthough. I'd just run returns over the wall, no need to risk drilling extra holes in glass, just me. Overflow on one side return on the other? Returns on each side drain in middle?
 
I'm by no means an expert but I have been reading a fair bit on overflows and return pumps. Everything seems to agree that you should be cycling 10x-20x your tank volume per hour through the sump drain and back into the tank via the return. A right angle turn on the drain will reduce flow rate by 30-50%. Even a 45 or 60 degree turn is significantly better. You might also consider flexible schedule 80 PVC (one source) as an alternative to bends with hard pipe.
 
I shoot for 5-8x through sump per hour, less noise, treats me well. Nothin wrong with more, but I don't think it's needed if you have powerheads as well
 
I'm running 2X an hour in my setup.

Like Mike said it probably would be best to route your plumbing over the rim. Bulkheads have a rim that lowers the return unnecessarily, if you run over the rim/top you can drill a siphon break very high up on the return and will have little to no back siphon. Also, I'd put the box on the middle since 75s are longer and more narrow than most modern reef tanks.

Is the tank glass? If so Tyler at Dolphin drills tanks as well as Chris at Aquatic central. Otherwise if the tank is acrylic you can get the tank drilled just about anywhere, all it takes is a hole saw.
 
thanks for the advice guys. the tank is glass, i will go talk to chris at ac about drilling the tank. ill let you all know how it turns out.

-steve
 
You must log in or register to reply here.
Back
Top