Concerned about tank flooding following power outage

[Rastareefing]

Hi,

I’ve recently started cycling a 300L Boyu tropical tank that’s been converted to marine using a pipework overflow system (pics below), I’ve got it running fine but I do have a concern.

The overflow needs to be primed (sucking on the longer tube) to start siphoning from the main tank into the sump when the pumps are turned on, no issues here and works fine BUT what happens if there’s a power outage for say, 30mins, and then the return pump comes back on but nobody is here to prime the overflow? Presumably the contents of my sump (about 40L give or take) would get pumped into the display and overfill it, causing it to flood?

If I’m right about this, is there any solution (such as hang-on-back overflows) which don’t share the same flaw?
Thanks

 

[Rastareefing]

Hi,

I’ve recently started cycling a 300L Boyu tropical tank that’s been converted to marine using a pipework overflow system (pics below), I’ve got it running fine but I do have a concern.

The overflow needs to be primed (sucking on the longer tube) to start siphoning from the main tank into the sump when the pumps are turned on, no issues here and works fine BUT what happens if there’s a power outage for say, 30mins, and then the return pump comes back on but nobody is here to prime the overflow? Presumably the contents of my sump (about 40L give or take) would get pumped into the display and overfill it, causing it to flood?

If I’m right about this, is there any solution (such as hang-on-back overflows) which don’t share the same flaw?
Thanks

 

[Rastareefing]

Just realised it’d only be the last chamber of the sump being pumped into the tank which shouldn’t be an issue any advice on a better overflow system would be appreciated though because this one is ugly as sin and I don’t really trust it.

 

[Mike Kearns]

Just realised it’d only be the last chamber of the sump being pumped into the tank which shouldn’t be an issue any advice on a better overflow system would be appreciated though because this one is ugly as sin and I don’t really trust it.

I hate to say it because I am a big DIY guy, but a HOB overflow box would be safer. I use the eshopps one currently and the way it is designed it does not loose the siphon in a power outage. It starts up again as soon as the water starts to flow into the box. The only time it breaks is if the siphon tube is removed.

 

[chipmunkofdoom2]

The overflow needs to be primed (sucking on the longer tube) to start siphoning from the main tank into the sump when the pumps are turned on, no issues here

That is an issue. It's a big issue. Your siphon should not break if your return pump stops. I have a HOB overflow box and haven't had to restart my siphon since I moved in April. I stop the pumps twice a day to feed.

 

[Mike Kearns]

Just out of curiosity, how is your return set up? If you don't have a siphon break on the return line, it can suck water back down into your sump and cause a flood that way if the pump shuts off. I found this out the hard way. I had to make a couple of holes in my return line just below the water level so the siphon breaks if the pump stops.

 

[Rastareefing]

That is an issue. It's a big issue. Your siphon should not break if your return pump stops. I have a HOB overflow box and haven't had to restart my siphon since I moved in April. I stop the pumps twice a day to feed.

I don’t know that it will for sure, I just assume that without the return pump operating it would no longer have the pressure required to maintain the siphon, and once the water level falls below the overflow this would be the case I’d imagine, unless my understanding is flawed?

I’m struggling to figure out how this would be any different on a HOB overflow though, if anyone could enlighten me I’d appreciate it. Plumbing isn’t my strong suit.

 

[Rastareefing]

Just out of curiosity, how is your return set up? If you don't have a siphon break on the return line, it can suck water back down into your sump and cause a flood that way if the pump shuts off. I found this out the hard way. I had to make a couple of holes in my return line just below the water level so the siphon breaks if the pump stops.

I learned this after turning the pump off when I’d just added the water earlier this week. 50 litres or so of natural sea water on my living room floor was a brutal if effective lesson.

I’ve drilled a small hole on the return pipe just below the water line, tested it twice today and it does the job by breaking the siphon.

 

[Rastareefing]

I hate to say it because I am a big DIY guy, but a HOB overflow box would be safer. I use the eshopps one currently and the way it is designed it does not loose the siphon in a power outage. It starts up again as soon as the water starts to flow into the box. The only time it breaks is if the siphon tube is removed.

This is awesome news, thanks! I’m trying to prioritise purchases due to budget but after dumping 50L of water onto the living room floor a few days ago my girlfriend is happy to cover the cost of a HOB overflow if it works out safer. Think I’ll take her up on the offer.

 

[Mike Kearns]

This is awesome news, thanks! I’m trying to prioritise purchases due to budget but after dumping 50L of water onto the living room floor a few days ago my girlfriend is happy to cover the cost of a HOB overflow if it works out safer. Think I’ll take her up on the offer.

Score! I would recommend getting one that has 2 bulkheads. It is way easier to make silent. My current tank only has one and sometimes it gurgles loudly

 

[Rastareefing]

Score! I would recommend getting one that has 2 bulkheads. It is way easier to make silent. My current tank only has one and sometimes it gurgles loudly

Good shout