Check valve puzzle....

[s.cruz]

I recently repaired the liner in my pondless waterfall system. I noticed with the pump off, both biofalls will empty back down into the main reservoir over a period of a day or so causing the reservoir to rise accordingly. I can fill both biofalls back up from the reservoir full again, so i know there is no leak and the system is closed. I replaced the check valve with a new one, and still the same situation. My question is: is when both biofalls empty into the reservoir and doesnt cause an overflow (system still closed), do I need to have a check valve anyway? Wont the pump adequately keep the water circulating in a continuous fashion? Or eventually would the biofalls empty enough so as to not overflow and i would lose the waterfall?

 

[Jeff Kraemer]

I recently repaired the liner in my pondless waterfall system. I noticed with the pump off, both biofalls will empty back down into the main reservoir over a period of a day or so causing the reservoir to rise accordingly. I can fill both biofalls back up from the reservoir full again, so i know there is no leak and the system is closed. I replaced the check valve with a new one, and still the same situation. My question is: is when both biofalls empty into the reservoir and doesnt cause an overflow (system still closed), do I need to have a check valve anyway? Wont the pump adequately keep the water circulating in a continuous fashion? Or eventually would the biofalls empty enough so as to not overflow and i would lose the waterfall?

What kind of check valve is it? Maybe it's a cheap one. If there is only one path from the reservoir to the falls, and it HAS to pass through the check valve back to the reservoir, it HAS to be the check valve. IF that is the way it is set up.

 

[s.cruz]

What kind of check valve is it? Maybe it's a cheap one. If there is only one path from the reservoir to the falls, and it HAS to pass through the check valve back to the reservoir, it HAS to be the check valve. IF that is the way it is set up.

It seems like a standard check valve, 1 1/2 in dia. with a flapper type mechanism inside. It was installed properly. I've read where if the back pressure isnt strong enough, it may not make a complete seal, but it seems like there is enough back pressure. The check valve is completely vertical. ...But again, if the reservoir can accommodate all the water in the system without overflowing when the pump is turned off (rarely, plan to keep pump on all the time) would a check valve be necessary anyway? after everthing has been glued together, hate to cut out pvc valve from hose again...

 

[Meyer Jordan]

If the reservoir is of sufficient capacity to accommodate transit water with enough reserve water to insure that the pump will not cavitate during normal use then a check valve is not really a necessity. What is the capacity of the reservoir in question? What is the estimated volume of transit water?

 

[s.cruz]

the transit water going through the pipes is only about 5 gal. so reservoir is adequate. The only thing I havent accounted for in the volume of the reservoir is that whoever built this ($%#$@*) used large rocks (50 to 70# a piece) to act as a base in the reservoir for the top layer of cobble to rest on. I would have to make sure to include that reduction in reservoir volume to accommodate the amount of water that would backflow from the 2 biofalls were the pump to turn off without a check valve. I think my liner is high enough all around, but will have to check. Isnt there lighter, porous type box supports available to support a few hundred pounds of cobble? Thanks for all your help!!

 

[Meyer Jordan]

the transit water going through the pipes is only about 5 gal. so reservoir is adequate. The only thing I havent accounted for in the volume of the reservoir is that whoever built this ($%#$@*) used large rocks (50 to 70# a piece) to act as a base in the reservoir for the top layer of cobble to rest on. I would have to make sure to include that reduction in reservoir volume to accommodate the amount of water that would backflow from the 2 biofalls were the pump to turn off without a check valve. I think my liner is high enough all around, but will have to check. Isnt there lighter, porous type box supports available to support a few hundred pounds of cobble? Thanks for all your help!!

Yes, they are sold under various trade names--Ecoblox, Matrix blocks, etc.. They are what is commonly used today in pondless and wetlands filters to support the upper level of gravel or cobbles.
This is what I always used. The least expensive of all the lot and just as functional.

 

[s.cruz]

Thanks a lot! Looks like your standard milk crate.....much better than boulders!

 

[Meyer Jordan]

Thanks a lot! Looks like your standard milk crate.....much better than boulders!

It is your standard milk crate. Easy Pro even admits this. These will support a considerable amount of weight.