How big of a hole?

Hello all,

I recently tried adding a check valve in my return line to see how that would work for keeping any backflow from the DT into my fuge in the case of pump failure or loss of electricity.

I cant believe how much noise this check valve makes so its definately coming out. I was wondering if I use the drilled hole method in my return line how big a hole it needs to be to successfully stop any back siphon. Also does it have to go through both sides or just one?

Any input is greatly appreciated. Its a 3/4 size return.

 

I would strongly suggest not using a check valve because they are known to fain. Since it was noisy as well that I guess is another reason not to use one

I used a 1/8" drill to make my anti siphon hole on my return. Drill right under the water line in the tank.
Drill both returns.

 

Awesome thanks for the input, much appreciated!

 

Yeah, and if you bought that check valve at something fish it was probably like $20-$25! I almost did until I saw the price. Instead I have a cheap (1.95 for 2 of them) clip that hold my return just barely below the water level and when I unplug my return pump and all the water siphons back in to the sump as much it can I am still good and no overflowing

 

Just keep the return close to the surface and maintain a little extra room in the sump and forget about both check valves and drilled holes. Both require maintenance and still fail where a air gap when the return is exposed to atmosphere does not fail and does not require cleaning or maintenance. My 100G backflows a maximum of 3.8 gallons worst case and thats easy to contain in a sump or fuge.

 

Nah bought that check valve at lowes, like 10 bucks so thought I would try it but its definately coming out.