The why, oh why, 38 stair, 290 gal build revised

[sphelps]

For your two pumps you don't need an electric valve, you need two standard check valves, one on each pump outlet. Then it's a simple matter of using a flow sensor or float switch to determined if the main pump shuts off and trigger the back up.

[reefwithareefer]

Originally Posted by sphelps

For your two pumps you don't need an electric valve, you need two standard check valves, one on each pump outlet. Then it's a simple matter of using a flow sensor or float switch to determined if the main pump shuts off and trigger the back up.

That is a great idea. Thanks.
I am assuming I should have the back flows, before the inlets?
Would I use the Apex BOB to trigger the back up?

[sphelps]

Not sure what you mean by back flows and I'm not an apex guy but I assume you need to use a BOB to connect some sort of sensor to determine pump failure. As far as valves and plumbing goes all you need are the two check valves, one on each pump output and that's it.

[reefwithareefer]

Originally Posted by sphelps

Not sure what you mean by back flows and I'm not an apex guy but I assume you need to use a BOB to connect some sort of sensor to determine pump failure. As far as valves and plumbing goes all you need are the two check valves, one on each pump output and that's it.

I mean back-flow preventor, same thing as a check valve.
Yes, I would use the Apex to sense the pump failure, so it could turn on the back up pump.

I was thinking the check valves would be at the inlet , just because of the way the two pumps plumbed together.

I was thinking that I had to have the check valves at the inlet side, but the more I think about it, the outlet side makes more sense. I just worry about stagnant water in one of the pumps getting into the tank.

[Leach29]

Originally Posted by reefwithareefer

Yes, I would use the Apex to sense the pump failure, so it could turn on the back up pump..

How do you use the apex to sense a pump failure? I'm thinking of a backup pump as well with my apex.

[reefwithareefer]

Originally Posted by Leach29

How do you use the apex to sense a pump failure? I'm thinking of a backup pump as well with my apex.

Not sure yet. Flow sensor of some sort in a union and wired to the apex BOB

Damn it, I was not going to make another project for myself for awhile.....

Dunderoz on this thread seems to have a solution

http://www.backyardaquaponics.com/fo...hp?f=8&t=12455

[sphelps]

The sensor could be as simple as float switch in the sump, if main pump fails sump level rises and triggers float which activates back up. Obliviously need a little coding to ensure it doesn't turn back off again once sump level drops or doesn't turn on during maintenance shut downs but that should be pretty basic. Alternatively profilux has a flow sensor available, perhaps it can be adapted to Apex or you could purchase another type of flow sensor that could be adapted.

If it were me I'd just run both pumps together, size the pumps or restrict the flow so each pump puts about 50% of the desired flow to the tank, if one fails you're left with 50% flow which obviously won't effect much. Then there's no controller or sensors to rely on and you achieve the same benefit with less reliability concerns.

[sphelps]

Originally Posted by reefwithareefer

I mean back-flow preventor, same thing as a check valve.
Yes, I would use the Apex to sense the pump failure, so it could turn on the back up pump.

I was thinking the check valves would be at the inlet , just because of the way the two pumps plumbed together.

I was thinking that I had to have the check valves at the inlet side, but the more I think about it, the outlet side makes more sense. I just worry about stagnant water in one of the pumps getting into the tank.

You wouldn't need any additional check valves or back flow preventers at the pump inlets, you only need a check valve on each pump outlet. In general check valves should only be installed on pump outputs, not inlets. With two pumps you'll always have stagnate water in the back up, not much you can do about it other than potentially program the back up to turn on for a minute or two each day. I see no reason why you can run both pumps together for brief amount of time provided it won't overload your overflow but most people design overflows for at least twice design.