30 gallon tank, is a 15 gallon sump enough?

[thatoneazn]

Hey guys,

I am looking to acquire a 30 gallon cube, and i already have a 15 gallon tank. Is that large enough to be the sump? Also, i am new to sumps, have had a nano tank most of my life, i understand that gravity feeds the sump, and the pump pushes the water back up. This is a problem, what happens if there is a power outage and i am not home. How do i prevent my sump overflowing my floor?

[Deep Thief]

Hey guys,

I am looking to acquire a 30 gallon cube, and i already have a 15 gallon tank. Is that large enough to be the sump? Also, i am new to sumps, have had a nano tank most of my life, i understand that gravity feeds the sump, and the pump pushes the water back up. This is a problem, what happens if there is a power outage and i am not home. How do i prevent my sump overflowing my floor?

15 gallon should be good, might depend on what you want to do with it though. As for how not to flood your sump. You won't, how you won't depends on how you get the water out of your tank and to the sump. The best way is via a corner overflow with the tank drilled and bulkheaded. As soon as the water drops below the level of the overflow, it quits running. There are other ways of getting the water out but you will need to decide how. I just suggested what I think is the best. Mark

[Whacked]

This is a problem, what happens if there is a power outage and i am not home. How do i prevent my sump overflowing my floor?

 

depends on setup.

Definately use a overflow box. that way the main tank will only drain to the bottom of the teeth in the overflow box.

Any return line whould have a couple small holes just under the waterline. those are siphon breaks so backpressure wont suck water backwards thru the return line.

design your sump so that in a power outage it will take the water from the drain/return lines plus any display water.

i.e. I calculated ~5g of water will drain from my 40B in a outage. In my 20L sump I have it set for 12g so I have ~8g to spare. I could have designed the sump baffles so it will normally hold more water and still hold drain water but I wanted a little safety factor.

 

Here is a excellent site that helps explain sumps and how they work

http://www.melevsreef.com/what_sump.html

[stanlalee]

15g sump is plenty big. hell why would anyone think a sump 50% the size of the main display would be inadequate. the general rule of thumb is the sump should be at least 30% the size of the main display. I have always used a 10g sump for my 30g. it fits well in the standard 36" 30g stand without fuss and it large enough to hold most skimmers suitable for a 30g, has adequate space so when the power goes out does not overflow at water level shown below.