Stenner pump specs question

[Chasarms]

I am in my first full year of pool self maintenance. I fully appreciate the TFP methods and have got my CYA to @40 using stabilizer and have been chlorinating 5-6 days of seven days since open using between 18-32 ounces of 12.5% liquid. Typically experiencing 1.0-2.0 ppm chlorine losses depending if 1 or 2 days between tests. The water is in the 78 degree range and the pool is 90% sun exposed. I expect it to get a bit more challenging as the Midwest heat comes on in a few weeks.

That said, the appeal of an automated system can’t be dismissed. My question is this: will a 25 psi Stenner be capable of injecting chlorine or do I need the 80 psi model? My pump pressure is typically in the 12-14 range and drifts to 16-18 as it needs to be washed. I have to assume the psi gauge is reasonably accurate for what it is. It came with the install.

Doughboy 2 hp pump with timer. 1.5” pvc plumbing. Set to run 8 hrs daily. So far, water is beautiful with CC levels never exceeding .2 ppm.

 

[GDN]

Need some others to weigh in here, but the pressure is between the pump and the filter, if the filter gets dirty the pressure goes up, but once the water is out of the filter I don't know that there is that much pressure, water should flow fairly easy on the return to the pool. For example if you took the guts out of the filter or the filter out of the line, would you see much pressure build up anywhere? I (and I think most) inject the chlorine after all equipment and just as the water is headed back to the pool, not under much pressure, so you'll likely be OK with either pump.

 

[Chasarms]

Need some others to weigh in here, but the pressure is between the pump and the filter, if the filter gets dirty the pressure goes up, but once the water is out of the filter I don't know that there is that much pressure, water should flow fairly easy on the return to the pool. For example if you took the guts out of the filter or the filter out of the line, would you see much pressure build up anywhere? I (and I think most) inject the chlorine after all equipment and just as the water is headed back to the pool, not under much pressure, so you'll likely be OK with either pump.

Yes, I would certainly inject bleach into the return following the filter. I just want to make sure 25psi would be more than enough.

I’m very grateful to anyone who shares their successes.

 

[jonpcar]

The difference in high psi vs low psi Stenner pump models is simply the check valve that they include in the injector to help prevent backflow of water into your Stenner tank, it isn’t a difference in the “power injection capability” of the Stenner pumps.

Your pressures won’t be anywhere close to 25psi after the filter given the numbers you have listed, unless you deadhead your pump by shutting off return valves. You will be fine with the 25psi rated pump...and you can always add the duckbill check valve if you want later. It does provide some protection for water backflow leaks that will occur when there is a hole in the tubing between the pump and the injection point at the cost (by some reports) of “gunking up” and having to be cleaned periodically. That “hole” would still have to be fixed in any case if you want to continue injecting chemicals.

Just in case...maybe @Stenner Tech Support will chime in.

 

[Stenner Tech Support]

Hi Jonpcar,

You are correct in the pressure rating of our pumps. It refers to the line pressure we can inject into.

On the return side of the pool, the pressure is usually less than 25 psi and an injection check valve is not needed. We hope this helps.