Power outages, sumps

[Duster]

I am in the planning stages of a 40g with all equipment under the tank, including a 20g sump. This is my first setup with under-tank plumbing, and I am wondering about the possibility of a sump overflowing in the event of a power outage or pump failure. If I am not home to shut off ball valves, will water from the main tank drain into the sump until the water level is below the bulkhead fitting supplying the sump? If this will happen, is it advisable to drill the bulkhead fitting near the top of the tank to limit drain-off? Can a float valve be rigged up in the sump that can close off the supply line? Any diagrams, parts lists, instructions, etc. will be appreciated by this newbie.

 

[Anonymous]

the easiest way to tell if it is gonna overflow the sump is to turn the pumps off :wink:

there needs to be ample space in there for the water in transit.
drilling an overflow in the sump and piping it to a drain is a fantastic idea but most people don't have that luxury.
i have flooded my livingroom on more than one occasion but it was never more than a gallon or two... as you may know this is a lot of water to have lying on the floor but considering the 100 gallons i have in the system i consider myself lucky... stupid but lucky.
my problem is i always want to utilize every bit of space possible to up my gallonage. learn from me.. it ain't worth it.

If I am not home to shut off ball valves, will water from the main tank drain into the sump until the water level is below the bulkhead fitting supplying the sump?

not necessarilly but possibly.
if the hole is on the bottom of the tank then you will likely have an overflow box of some sort. if the box is watertight it will hold the water at a constant level near the top.

If this will happen, is it advisable to drill the bulkhead fitting near the top of the tank to limit drain-off?

some guys do this.
i drilled the bottom to eliminate piping in the back of the tank.

Can a float valve be rigged up in the sump that can close off the supply line?

if oyu mean the supply coming off the pump discharge then i see no reason for a float valve as it will just shut the pump discharge line when the motor is switched on, a check valve would be a better choice.
now, if you actually are referring to the sump return line from the tank to the sump then i would say i haven't ever seen anyone install one. it would have to be big.

the discharge lines are not as difficult to deal with. if you keep them high enough they won't siphon all your water out and if you drill a hole in the line(s) somewhere it can stop siphoning altogether... as long as the hole(s) stays a hole. i don't use check valves.

 

[Duster]

Thanks Podman. I never even thought of drilling an overflow in the sump and piping it to a drain. I can't believe I didn't think of that, considering I've already drilled a hole through my living room floor and ran a drain hose into the basement for my dehumidifier. I can easily do the same thing behind my aquarium stand for an overlow drain. No problem. You helped me solve this much easier than I was expecting.

 

[danmhippo]

It's always a good idea to run a power failure simulation after you did all your plumbing, before you start the actual process of stocking livestock.

It's better to have a flood when it's just freshwater that you have to worry about.

 

[Anonymous]

the best thing I did form my external sump/refug was just buy a HOB overflow skimmer box. With a drilled tank you adjust the overflows to do the same thing. Both basicaly insure the overflow stops after the tank goes down to a certain level. And maintain the overflow to resume normal operation when poser returns.

that way you limit the amount of water that flows to the sump during power outages. So the sump has to be able to have the water level rise during power outages. But that is something eaily tested during set up.

 

[Anonymous]

Don't forget that the return line will act as a siphon during a power outage. There are a few things you can do to help that situation. I use anti-siphon holes right at the water line to kill the siphon if the pump stops.

 

[Duster]

What is an anit-siphon hold and where do I get them?

 

[Anonymous]

What is an anit-siphon hold and where do I get them?

i would think he meant "holes".

 

[Bojangles]

i would think he meant "holes".

Where exactly do you drill these holes again? I've also heard of this and I'm in the process of setting up a 60g ref / sump to my 200g.

You know I"m not worried about flooding my sump but I am very afraid of my overflow losing syphon when the power goes. In that case the return pump would flood the main tank.

The overflow I'm using is Innovative Aquarium Products. The LFS said it was rated to 1200g.

 

[danmhippo]

Drill a hole to act as siphon break about 1" below the water line. When poweroutages happened, water will drain back via return pump, and will break siphon when the siphon break hole is exposed to air.

 

[Tackett]

drilling an overflow in the sump and piping it to a drain is a fantastic idea but most people don't have that luxury.

GENIUS sheer genius. I would have never thought of that in a million years. :idea:

 

[Bojangles]

Ok I built a sump / refug out of a 60g all glass tank and heres what happened. I sealed the baffles in completely so no sand would leak from the refug into the bubble traps. When I filled it with water only the center filled, spilling no water into the traps.

Just before the top both seals on the left and right blew due to pressure. True that I did not use much silicone when I installed the baffles, but this could be easily avoided by drilling a hole into the baffle walls on both sides of the refugium section OR 3 smaller holes on each wall like I did. They allow for water flow and the sump filled at the same speed as the rest of the refugium YAY no pressure!@!

hope my experience helps ya!