New Sump Setup - Flood Prevention

omniphil · Jul 7, 2023

I stumbled across a good deal on a Sump and decided its time to upgrade from my canister filter.
Looking for some mostly foolproof ways to prevents floods...

I have a 32 gallon main tank and I ended up with a 30 gallon sump
Overkill I know, but one of the main goals is to increase water volume as I have no central AC at home and I want the water to heat up slower to hopefully not need to keep turning on the window AC unit. (Or at least less...)

So with those sizes in mind I am pretty confident that if power goes out and the return pump stops with the sump being so large it will easily hold extra water draining from the tank. What I want to prevent is the main tank and the overflow box from over flowing if something gets clogged/siphon break...

I picked up an eshopps PF800 overflow box. If the drain got clogged for whatever reason I'd have a tank overflow and if the siphon broke I think I'd have the same.
I was thinking I could put a water level sensor in the main tank and if it gets too high shutdown the return pump?
Would I also need a water level sensor in the overflow box? Is there a scenario in which the overflow box would overflow when the main tank doesn't?

Any other potential flood scenarios I am missing?

Bonus question is that the sump has two 1 inch drains with socks. PF800 has one drain. Can I just ignore one of the sump drains or maybe add a T to spilt the drain to both? (I didn't get a PF1000 with 2 drains as I figured I wouldn't be flowing enough water through it to keep the siphon going)

Suohhen · Jul 7, 2023

Regarding overflowing the sump you need to consider what is the maximum amount of water that would drain out if your siphon break were. I Y one of my returns after the bulkhead and point one side up towards the surface to create more substantial/consistent rippling which doubles as a backup siphon break.
For the tank yes the method you described is correct and you don't need a sensor in the overflow but it is advisable to use two sensors for redundancy as they commonly get jammed.
The reason they include 2 filter socks is that many tanks run multiple drains for noise mitigation (example Durso and Herbie.) You don't need to use both chambers.

omniphil · Jul 7, 2023

I have a 36 gallon sump, so I assume under normal operation it's probably running at half full? So I should have 18 gallons of free space and there's no way under pump or power failure i'd drain that much from the main 30 gallon tank. a few gallons at most would be my guess...

Having 2 level sensors is a really good idea. I like redundancy... I suppose I could also put one in the sump as if it's water level starts getting unusually low it means the overflow isn't draining properly.

I hadn't considered noise reduction, so maybe I should use some sort of T or splitter in the drain line to feed both drains to keep noise down.

Suohhen · Jul 7, 2023

For sure redundancy is key to long term success in this hobby and a sensor in the sump for low level detection is a great idea to prevent run dry as well.
Noise reduction is a factor of the overflow pipe design. The 3 most common setups are commonly referred to as Durso, Herbie, and BeanAnimal