Sump Overflow Protection - Advice Wanted

[Taschi]

Hello, Reefers!

I'm fairly new to the hobby, and am currently in the process of researching all the parts I want to have in my sump pump. However, the one thing that I haven't read or seen anywhere (and please don't laugh lol), is placing the sump pump tank inside a larger container in the event of an overflow.

What I'm trying to say is this:

Take your sump pump tank and place it inside let's say an appropriately sized plastic container. That way if the power goes out and your other safeties fail, while the siphon continues filling up your sump tank, when your sump over flows, it goes into the container housing your sump rather than all over your floor.


I tried researching instances where someone may have done this, but I could not finding anything. Is there a reason or something I'm overlooking? To me it sounds like a great idea, but again, I'm new.
Thoughts? Thank you.

 

[twobytwo]

The water level in your sump will be low enough that if power goes out, the amount of water that drains from the tank is not enough to overflow the sump. My 40g sump operates half-full normally. If power goes out, it can easily hold the amount of water above my overflow and drain in my 120g

 

[Taschi]

Ah okay, I understand what you're saying, that definitely makes way more sense.

I guess I'm just paranoid about water flowing all over the place, so I thought it was a good idea. But now that I think about it, my sump should be able to hold all of the water that would run into it.

That makes me feel so much better, thank you!

 

[bevo5]

Wait - I'm confused. Are you saying you want to put your sump inside a larger tank? Why not just use the larger tank as your sump?

You need to design the system so that this isn't even an issue to begin with. Your sump should hold all of the backflow when the pumps are off. Don't rely on check valves or anything else but 100% fail safe empty space. You want to make sure your returns are placed high enough so the siphon is broken relatively soon...that will limit the water that gets down there.

 

[AZDesertRat]

Your sump should always have enough freeboard or spare room to contain the small amount of backflow until your return is exposed to atmosphere and the siphon breaks. In my case I have a 60" long 100g display and a 30g sump that operates with about 18 gallons in it. My returns are 3/4" below the surface.
So 60" long x 18" front to back x 3/4" down before exposed divided by 231 = a maximum of 3.5 gallons that can possibly flow back to the sump. The sump has 12 gallons of space so floods are out of the picture.

 

[Waters]

As bevo5 stated, just make sure your returns are either at the water surface, or you drill a siphon break in each one next to the surface of the water. That will prevent the entire tank from siphoning into your sump. Make sure you test everything by simulating power outages.

 

[AZDesertRat]

Never rely on drilled holes, just like check valves they are a false sense of security and can and do fail no matter how well maintained, besides being noisy. Nothing compares to a simple air gap, water cannot jump uphill and the gap requires no maintenance or cleaning.

 

[Taschi]

No, I wouldn't use a larger tank, I would have used a cheap plastic bin I already own in my home. But considering that if the power were to go out, my sump would be large enough to hold the water that would run through. I was just paranoid about water constantly flowing into my sump tank, so I started frantically brainstorming without coming to the conclusion that the flow would eventually have to stop lol.

You guys are all so awesome with your ideas. I will definitely check how the sump will hold up by simulating an outage - that's great advice.
It's obviously not put together yet, but hopefully in the next month or so, I'll have all of the parts I want

 

[debby]

any fail safe system, must be tested and re-tested to insure it's working. That goes for any check-valve, siphon break and of course, having enough room in the sump to prevent a flood should all else fail.

Like a belt, suspenders and a tight-pair-of-ahem....never rely on one system. Two is good - three is best.

 

[AZDesertRat]

An air gap doesn't need a back up, it can't fail.

 

[Hethari]

Either you put check valve after the pump or you can make a small hole in the outflow at water surface this will be enough to prevent back flow

 

[Hethari]

 

[Hethari]

But air gap is the best never fail

 

[CodyRVA]

+1 to what most everyone said... check valves, do some simple math on your sump volume and how much drainage would occur during a pump outage or failure. Another idea that I picked up and implemented... Line the bottom of your stand with pond liner. That way if your sump does over flow, the pond liner will catch it; essentially turning the bottom of your stand into another holding area for water.

 

[john.m.cole3]

An air gap doesn't need a back up, it can't fail.

I don't understand how to create an air gap. I've heard you mention this in other threads and still don't understand where the air gap is located or how it's created.

 

[AZDesertRat]

The air gap is created once the display level drops and the return is exposed to air or atmosphere. The siphon breaks at that point and backsiphonage or backflow stops. Water cannot jump up to the return so it is foolproof. As long as you maintain that amount of room in the sump you are good.

 

[beaslbob]

Air gaps are created with HOB overflows. Air tends to collect at the high point. From small bubbles and the like. Eventually they can combine causing a break in the hob siphon. I fixed that problem by using a maxi jet powerhead with the "bubbler" to suck out any air at the top of the utube overflow.

More to the point you should adjust your sump/display system to where there are no floods. Which makes the extra basket unnecessary. But you still might want to put the sump on some kinda plastic device to prevent splashes from reaching the carpet or floor. Building supply stores have those for washing machines and they even come with a pvc bulkhead to boot.

When adjusting:

1) make sure the sump does not flood with power out. Overflow should stop and there should be no siphon in the return lines.

2) make sure normal operation returns when the power returns.

and finally (this one I forgot LOL)

3) make sure the display (upper container) does not flood when the over flow fails. (blockage, siphon failure). The key here is to make sure the return pump runs dry before the display floods. So remove water until that is the case. Then return to normal operation and mark the water level in the sump. From that point on never never add water above that line.

If you make those three adjustments, no check or other valves are required. No level floats are requires either. The system just functions in such a manner to prevent floods.

One thing that can screw that up is automatic top offs (atos). If the drain fails, the ato will "sense" a low water level and add water to the system. Depending on how much the ato can hold, the display could flood. I have never used an ato but it would seem to me to be a good idea to use some kind of drip system to replace evaporative losses as the occur. At least that way it could take a day or two before the display floods giving you time to correct the drain failure.

my .02

 

[john.m.cole3]

The air gap is created once the display level drops and the return is exposed to air or atmosphere. The siphon breaks at that point and backsiphonage or backflow stops. Water cannot jump up to the return so it is foolproof. As long as you maintain that amount of room in the sump you are good.

Ok, cool I made sure I had enough room in my sump from your LxWxH/231 formula (very nice BTW). My biggest concern is that if I have a power failure, my sump rises about 3 inches, and when my skimmer kicks back in, I'm afraid it might overflow for a little bit. Guess I need to do a mock power outage and see what happens (duh)

 

[AZDesertRat]

My skimmer is in sump so any overflow goes back to the sump so no big deal. I suppose I could put the skimmer on my RKL controller with a delayed start once power comes on but it really doesn't concern me much.

 

[Sgt Jonny]

Check out this video on that subject...