PDA

View Full Version : How much water is drained for power outage?


MJD 1
01/31/2007, 08:25 PM
I have a 90g AGA with the standard megaflow. I am currently plumbing and I am wondering how many gallons would leave the display and enter the sump. I dont want any floods!!!

I heard of the equation the height of your overflow teeth or where the hole is x wide x length of tank divided by 231. But this would equal 82 gallons!?!?!?

I know this is not possible so does anyone know how much water is drained. All 90g people please chime in or anyone else with an idea!

Thanks,

MJD

JohnnyM2
01/31/2007, 08:48 PM
My 90 gal is 18"X48". When operating, the water in the main tank is halfway up the overflow teeth so with the pump off 18"X48"X.5"=432 cu inches flows back to the sump. Since 1 cu ft=1728 cu in=7.48 gals then 1728cu. inches/7.48 gals=231 cu inches per gallon. Divide the tank return, 432 cu inches by 231 and you get less than 2 gals. Yours is probably simpler. Note that my standpipe is a durso so the entire overflow chamber does not flow back. Also my return is drilled to prevent siphoning. My skimmer also settles down and returns some water to the sump. Hope it helps. If this information is useless, you can just ignore it.

AZDesertRat
01/31/2007, 08:48 PM
You only want the distance from the water surface down to the bottom of the overflow teeth in inches. So it would probably be something like 1.5" x 48" x 18" divided by 231 or 5.6 gallons. The other distance is how low are your returns in the water? If its not drilled with a siphon break hole or kept shallow it could also siphon back on the discharge side. I prefer to keep my returns close to the surface.

sjm817
01/31/2007, 09:03 PM
3.7G for every 1" of water drained back.

UCanDoIt
02/01/2007, 12:19 AM
<a href=showthread.php?s=&postid=9128424#post9128424 target=_blank>Originally posted</a> by MJD 1
..... I heard of the equation the height of your overflow teeth or where the hole is x wide x length of tank divided by 231. But this would equal 82 gallons!?!?!?

I know this is not possible so does anyone know how much water is drained. All 90g people please chime in or anyone else with an idea!

Thanks,

MJD Glad you figure out that 82g drain from a 90g tank is impossible. :lol: Maybe your calculation is 8.2g?

MJD 1
02/01/2007, 01:39 PM
Thanks everyone,

JohnnyM2 do yu have the AGA with megaflow or just a reg. 90?
So I learned that I cant lose more than 9 gallons, I think...

MJD