Quick question regarding a power outage and sump

[CoRPS]

I'm planning out my 90g and 55g fuge. I'm trying to figure out how much water will flow from my 90g into my 55g if the power were to shut off. My plans are to use a durso standpipe which should cut back on noise and the amount of water that will flow down if the pump turns off.

The reason I'm a bit concerned is that I will need the water level in the sump to be high enough to use my HOB skimmer until I can afford to buy a in sump skimmer.

Just a note: I'm planning on building the stand 4' tall.

 

[kraze3]

The amount of water will depend on where you drill your bulkheads and how you have the drain on the inside of the tank. If there is oging to be an overflow box, you can make thisthe height u want the water in the tank and when power i slost on a little will drain to the sump. You can also use elbows turned up on the insde of the bulkhead to reduce the amount of water drained.

For the return you also have some options. The elbow and how low you drill will make a difference. My bulkhead is dirlled somewhat low but I have a piece of locline connected on the inside. the loc-line curves toward the surface and then back down behnd my rock work. I have drilled a small hole where the loc-line meets the waters surface. In a power outtage the hole sucks in air breaking siphon, reducing the amount of water draining to sump.

 

[CoRPS]

The hole for the bulkhead is in the bottom of the tank. However, that really doesn't matter because of the durso standpipe.

As for the back siphon from the pump, I didn't even think of that. I'll definitely have to take that into consideration.

 

[jasoncw]

How high is the water level compared to the bottom of the slits of your overflow(s)? Assuming 2", you would need to account for roughly 7.5g from the tank (48"x18"x2"/231) plus the volume of the drain/return lines.

So, for the 55g, 3" would provide room for close to 7.5g, so you would want at least 4". Probably more if you want to account for an in-sump skimmer, since it will take up some of the volume.

 

[CoRPS]

It's actually only about a 1/2" from where I usually fill my tanks.

 

[kraze3]

One way to figure out how much is draining is make a mark on your sump where the water is now. Then cut the power. Measure from your mark to the top of the water surface and use the calculator to figure out how many gallons. Then you can account for a little extra to be sure and leave at least that much room in your sump. Or you can adjust the pipes in your display so less will drain.

 

[CoRPS]

I don't have the tank setup yet! Hell I don't even have the stand yet

I'm just trying to envision everything now so I know what to expect when the time comes to make the change over.