Check Valves...need advise!?!

[roadrunner1659]

I'm working on my new fuge/sump...i have a question at my return line...

im using a mag 7 and connecting right off of that im threading a ball valve, my LFS also through in what i think to be a check valve...

(this is not your ordinary LFS)

...anyway he gave me a 3 inche pvc piece and told me to put that inbetween the ball valve and the check valve (he told me it isn't a good idea to have a check valve under water)...

what i was wondering is whether or not check valves truely work and if they malfunction is it only by not closing with backflow?

i created my fuge/sump to work with 25 gallons (its a 33 gal tank which i figure to hold more then enough water when power goes out)

so what should i do? would it be smart to attach the check valve or not?

(i am also going to drill a hole in my return line that is in my tank to break the siphon - at what depth in the tank below the water line should that hole be)

Thanks!

 

[Khai]

Well, my take from Check valves is that the can only add problems:

Malfunction/Reduce flow...

I just used normal ball gates:

http://reefcentral.com/forums/showthread.php?s=&threadid=837063

 

[roadrunner1659]

thanks khai! and your setup and plumbing is crazy!

 

[roadrunner1659]

you wouldn't happen to know were my siphon break hole should be compaired to my water line and what a reccommended hole size would be? would you?

 

[bertoni]

I would put more than one in the tube, and right around the water level should be fine. I think most people put one just under the water line. The smallest drill bit you have should be fine, IMO.

 

[roadrunner1659]

thanks bertoni! i will probably put 2 holes in my tube and i will do it right at my water line!