How Many Gallons in Aqueon Overflow 75 Gallon Reef Ready

[Asm481]

Trying to build a sump for a new 75 gallon reef ready tank from Aqueon. How much space do I need to have in sump for the overflow in the tank if I don't glue the risers in the overflow. I don't want a flood of course! I am using a 20 gallon long with glass dividers.

 

[Saltyreef]

Trying to build a sump for a new 75 gallon reef ready tank from Aqueon. How much space do I need to have in sump for the overflow in the tank if I don't glue the risers in the overflow. I don't want a flood of course! I am using a 20 gallon long with glass dividers.

It depends where your siphon break is installed. This will determine how much water backflows from the display into the return section of the sump with power disconnected.

 

[mrjohnreed]

I am following because I am in the same boat. I have a 75 gallon with a new 20 gallon long sump that I am putting together now.

 

[His Coral Highness]

Use this formula

 

[PotatoPig]

I am following because I am in the same boat. I have a 75 gallon with a new 20 gallon long sump that I am putting together now.

This depends 100% on how far your return nozzle is below the water line, or if you drill a siphon break hole how far that is below the water line.

Every inch water your 75 DT has to fall by to break siphon will raise water in your 20L by 2.4”

I have the same 75/20L setup, I found drilling a siphon hole big enough to reliably break soon after hitting air meant so much water flowed out of that it limited the push from the return nozzle, so just removed the nozzle and have the return piece shoot water straight down, submerged by about 3/4”

 

[PotatoPig]

Use this formula

You can save a little math and working out what the water volume means for the sump if you do the following:

Siphon break depth x (Display length x width) / (Sump length x width)

This will tell you directly how much the water level in the sump will rise.

Eg, for the tanks in question, assuming a nozzle depth of 2”
2 x (48 x 18)/(30x12) = 4.8” water rise in sump.

It also works without modification when using metric units, just it’ll tell you how many cm your sump water level will rise.

 

[Asm481]

I was never concerned with the siphoning back through returns, I keep them way up top just barely below surface. My concern was the space inside the overflow which would eventually leak down in a long shutdown or if I had a fish jump in and I wanted to pull the durso out to flush the down. I know how to do math but it is not straight or square. In the end I set it up and marked the change. Fills the sump about 2 inches.