Sump return – Siphon Break, Check Value, or What?

[redfishbluefish]

Current setup does not have a siphon break or check valve for the return line coming from the sump. When power is killed, it results in maybe 5 – 6 gallons siphoned from the display into the sump. With the next build…a bigger display…I want to install a siphon break, check valve or something, to keep the water from filling up the sump when the power is killed.

What’s your opinion of siphon breaks verses check valves (or even some other option I don’t know about)? I’m ignorant with both and don’t know what would work best. For the siphon break: How big a hole?; Where do you drill it? For the check valve: Does it restrict flow?; Are there any shortcoming have a check valve?; Do they clog up?

Any advice would be appreciated.

 

[concept3]

I used to have a check valve, but they reduced the output flow of the pump a little much for my liking. My current tank has no check valve anymore. I also had a siphon hole on a few of my returns, but found that they got clogged anyways, I just eliminated them.

I know of a fellow reefer who had a 1/4" hole as a siphon break, but he neglected to clean it out on a regular basis. Tank lost 30% of its water volume to the carpet. The hole got plugged with some detritus and algae grew over the detritus

I still think the best fail-safe is a larger sump if possible, I myself lose about 3-4 gallons to the sump when the pump is turned off (for feeding), and I still have about 10-12 gallons of leeway left. My tank holds about 92 gallons and the sump holds about 25 or so when full.

 

[Brian]

Even though I don't really need it I have a siphon break. It's about an 1/8" hole. Like Merv stated, you have to keep it clean...if that is truly what you are depending on to not overflow your sump.

 

[Phyl]

With the 550g system we have plenty of space in the sump for overflow (about 50g of which we might use 20g). But with the 65 in our bedroom we use siphon holes that we keep cleaned out and then we keep the returns close to the surface so that they break siphon shortly after the water volume falls. We only can fit a 10g tank under there and there's not much room for error.