Ways to have a flood...

[ucdcrew]

I have an HOB overflow

1) Overflow gets clogged, all water from sump goes into DT.
b) Back siphon on return line during power failure.
III) Some sort of catastrophic pipe catastrophe
iv. Not enough room in sump for drain down.

Am I missing a one?

My ways to deal plan:
1) High water float valve on DT to stop pump.
b) Multiple break siphon holes on return line in DT
III) Pray to the PVC gods (and renter's insurance)
iv. As someone so eloquently put it, "Don't cross the line" (in the sump)

:worried2:

[Lynxone]

Leave enough room in sump for overflow

Raise your return pump so that it doesn't run sump dry Float in display too

I run an aqualifter pump to keep air from accumulating in my hob and also helps on start up

And lots of floats throughout to detect low and high levels in sump.

[dkeller_nc]

Honestly, the best way to deal with the risk of a HOB overflow is to upgrade to a drilled tank with a sump. Properly designed, a drilled tank has a much, much lower risk of flooding.

Essentially, the only way it can happen is for your bulkheads on the bottom of the overflow to leak, and this will only go so far as dropping the tank level to the bottom of the teeth in the overflow.

Yes, you can still have one of the standpipes clog with algae/snails, but that's why most modern overflow setups have one or more "emergency" drains.

And, if you have to convince a significant other to let you upgrade, not having the carpet/wood floors get saturated with saltwater that will smell like a wharf within a day is powerful justification. :)

[Lynxone]

While I agree that a drilled tank is best, a properly set up hob will work safely if you use some safety measures and you keep an eye out for problems. If I had it to do over, I would drill my tank. But if your tank is already established, you can run a hob overflow without losing sleep at night lol. I've been running mine for years and many people on here do it as well. Just use common sense and plan for all worst case scenarios.

[Lynxone]

Oh, also just out of curiosity, what hob are you using?

[dkeller_nc]

As Lynxone has alluded to, the failure rate of HOB overflows significantly depends on the design. Lifereef overflows are about the best design out there as far as reliability, but it's still possible to break the siphon in one of these in certain circumstances - that's generally a situation where return flow pump has issues, the flow slows down to the point where the HOB overflow cannot clear bubbles, and the siphon breaks.

An alternate design uses an aqualifter pump to prevent bubble accumulation. Problem is, aqualifter pumps aren't that reliable, at least from the standpoint of putting a few thousand in water damage on the table.

Do yourself a favor - upgrade your tank to a drilled version. While I don't personally like the looks of the Marineland "reef ready" tanks, the price is right, especially compared to most of the other pieces of equipment that's necessary for running a reef tank.

[Dapg8gt]

Lifereef or eshopps continuous syphon is about the safest bet in the hob world. I've been running the eshopps on my frag tank for almost 5 years and never came close to having a flood. Anything that needs a pump to stay primed is eventually going to fail..

But a drilled tank is always best..

[ucdcrew]

I have an eshopps overflow. Although I may put my reefing on hold. I live in a second floor apartment. I had a minor catastrophe with a freshwater tank last night that got me thinking. Ironically, I had just filled up the freshwater tank (a 20gL) right before posting this. I remember thinking it was strange that that tank was 1 inch down from the lip and the other wasn't. So like a genius, I refilled it. Down about an inch this morning, but can't feel the water coming out of the tank and the drip looks like its from the filter. I'll find out when I get home from work!

[ca1ore]

Hate HOB overflows, always risk of flooding IMO. Pretty easy these days to drill a tank, so that would always be my choice. If I were left with no alternative, I'd make sure to have the main pump switched with a float switch.

[ca1ore]

I have an HOB overflow

1) Overflow gets clogged, all water from sump goes into DT.
b) Back siphon on return line during power failure.
III) Some sort of catastrophic pipe catastrophe
iv. Not enough room in sump for drain down.

Am I missing a one?

My ways to deal plan:
1) High water float valve on DT to stop pump.
b) Multiple break siphon holes on return line in DT
III) Pray to the PVC gods (and renter's insurance)
iv. As someone so eloquently put it, "Don't cross the line" (in the sump)

:worried2:

Migh want a low level float in the sump also.

[ucdcrew]

The tank is already upstairs, and its heavy. And I just moved here so I don't have any friends (so sad...lol). Guess I could join the reef club to see if someone will help me.

[sleepydoc]

Honestly, the best way to deal with the risk of a HOB overflow is to upgrade to a drilled tank with a sump. Properly designed, a drilled tank has a much, much lower risk of flooding.

Essentially, the only way it can happen is for your bulkheads on the bottom of the overflow to leak, and this will only go so far as dropping the tank level to the bottom of the teeth in the overflow.

Yes, you can still have one of the standpipes clog with algae/snails, but that's why most modern overflow setups have one or more "emergency" drains.

And, if you have to convince a significant other to let you upgrade, not having the carpet/wood floors get saturated with saltwater that will smell like a wharf within a day is powerful justification. :)

+1
What size tank do you have? If you haven't filled it yet, I would give serious consideration to drilling it; I think you'll be a lot happier in the long run.

Especially if you're in a 2nd floor apt, Consider getting a water alarm to alert you if it's getting wet under the tank.

[ucdcrew]

I'm gonna get a controller that has inputs for water sensors, so that i can be informed of the situation if I am at work via cell phone. I got the tank up by asking my neighbor for help, but I'm pretty sure he was wasted so I'm not sure I want to ask again...LOL! Especially going downstairs.

[BlindZide]

I run a CPR CS50 with an AquaLifter pump. The biggest issue with this setup is that the pump may get debris in it and cause it to seize. I purchased a pre filter for it so it will collect debris before it gets to the pump. I also raised the return pump in my sump so it will only pump a few inches into the DT so the DT wont overflow if the pump fails. I test it every week just to make sure it is in working order.

[2x2]

The biggest risk is power failure and making sure your sump can handle the back flow. It wont loose siphon. You can worry about it, but it won't happen. (Eshopps). When you shut down the tank and restart. hob restarts every time. its hard to break the siphon on the utube. Getting clogged is another story. Very unlikely but possible. I take mine off every three to six months and clean and inspect. I've ran one for two years now without any issues.

Raising your pump could help reduce the chance of a bad overflow but make sure you have an ATO. If you forget to look under the tank you could run the pump dry with evaporation.

The goal should be to have a drilled tank!

[Sk8r]

Water alarm, from Amazon, under 15.00. Put it on your floor. If a puddle causes the contacts to make contact, it screams like a banshee. Won't help while you're at work, but it'll help if you're at home asleep.

[dkeller_nc]

The tank is already upstairs, and its heavy. And I just moved here so I don't have any friends (so sad...lol). Guess I could join the reef club to see if someone will help me.

You didn't say what size tank you have, and what brand. Certain brands have tempered bottoms in the larger tank sizes - there's a test you can do with a laptop and a pair of polarized sunglasses (it's a youtube video). Tempered glass cannot be drilled, but this is just the bottom of the tank. The latest trend in overflows is a so-called "coast to coast" overflow with a Bean Animal drain set-up. Here's a description from his website:

http://www.beananimal.com/projects/silent-and-fail-safe-aquarium-overflow-system.aspx

If what you're setting up is a fairly large tank (75 gallons or more), this is a very practical way to drill your tank. You could drill the back or side of the tank in the room that it's in - all you have to do is bribe someone with a 6-pack to help you set the tank on its side. I suppose it's possible, but I've not heard of any aquarium brand that has tempered sides, so you should be able to drill your existing tank.

And because the Bean Animal overflow set-up has 3 drains, the probability of a flooding disaster is very remote. An additional advantage is that it's silent, or nearly so.