Stenner Pump for chlorine questions

[leashy333]

I just got a used Stenner 45MPH10 pump to use for adding bleach to the pool automatically. I called Stenner to find out how to hook it up, and they recommended adding a PVC T in the return line going from the pump back to the pool and not to use a check valve on that T because they said most pools have lower than 25 PSI pressure and the check valve is for 25-100 PSI and when the line pressure is less than that it can cause premature failure of the pump. Rather than their check valve, they recommended their injection valve (part UCAK300). He said I could potentially use part "bcv14tvh", which he called a ball check valve and should be safer than using the "duckbill" check valve for this application.

Question, for you guys who have these pumps:
1. Isnt water pressure on the line from pool to the return jet high enough? I have an above ground pool with a 1HP pump really close to the pool and it seems to me that a very significant amount of water comes out of the jet, seems more than a faucet on the house. But maybe its less than I think. The gauge on the sand filter stays around 21 PSI, but i dunno if that means the jet line is 21 PSI or less...
2. If i didnt have a check valve, wouldnt it push pool water backwards into the bleach tubing, and then into the bleach bucket? The pressure seems so high that it seems to me that it would want to travel up my tubing...i mean...obviosuly if i drilled a hole in the return line, its going to spurt water everywhere, so seems w/o a check valve, water is going to backflow.
3. I had also thought about just running the tubing into the side of my skimmer basket, near the top, so that it would just drip into the skimmer. Is there is reason not to do this? I know its not the best to have bleach going through the pump, but we're talking like 1/2 gallon of 6 or 8.25% bleach over the course of 6-8 hrs. So doesnt seem to me like that would hurt anything. I dont have a heater, so it would only be flowing through the pump and sand filter. I asked Stenner about this and he said it could end up building deposits on the end of the line and clog it up...not sure what thats about.


Thanks for your help on this!

 

[leashy333]

So no replies, but i will answer my own questions, and see if anyone has any comments.

I called Stenner and they said unless the pressure is > 25 PSI, all i need is the injector valve (no check valve needed) because the rollers in the pump squeeze the tube and essentially seals it off enough that backflow would not be an issue. I guess it makes sense...if the feed line is full of bleach and sealed off at the pump, water cant push up into the feed line because its already full.

Also, in researching this more, I've found that a lot of people say they have to clean the injector / check valve regularly with acid solution due to the fact that when high PH bleach hits the low PH water, calcium deposits build up and eventually restrict the flow and can cause the pump tube to leak/rupture eventually. So why would I want to inject the bleach into the return line when I could just have it drip from the air into the pool, avoiding the contact of the tube with water, and it seems like avoiding the need to do periodic cleaning/maintenance of that valve. I want this to be as "trouble free" as possible. And rather than having it drip into the skimmer basket like i said above, here is my current thought: This is for an above ground pool, and there is a small gap between the pool wall and rail, so I plan to run the chlorine supply feed line under the rail and out a couple inches away from the pool wall/liner (to avoid bleach on the liner), and several inches above the water line. Essentially having it drip into the water where the return jet is. Given that the rail sticks out over the water a couple inches, it will basically not be visible.

 

[rphpool]

What you are planning will work just fine ( skimmer or poolside ). In truth I only have to clean my injector once per year so not really a big maintenance deal.

 

[leashy333]

What you are planning will work just fine ( skimmer or poolside ). In truth I only have to clean my injector once per year so not really a big maintenance deal.

Oh thats good to know. The posts I had read were on another forum, and it may have been in an application where the pump was being used in a more industrial application. I cant find it right now, but more than one person said they have to clean the injection valve every 2-3 weeks and therefore had two of them, so they could swap one out quickly while the other was being cleaned.

 

[Topher55]

I have a 10gpd stenner, I'm away from the house so can't check model number now. I have had it for threeish years now, I have found the duckbill style check valve to be worthless... the salt crystals that collect in the bleach tank regularly stick in the duckbill rendering it useless. The true check valve is the rollers pinching the tube off in the pump head. Once I caught my bulk tank slowly filling back up, I thought yea it's the check valve so I pulled it off and sure enough full of chunks. I switched it out and a week later same thing. I dug a little deeper and did some research, turns out my tube was worn letting water flow back through it. Replaced that tube a little over a year ago and no problems since. First one lasted two years.

I have the stenner plumbed into my empty inline puck chlorination. I use a VS pump that I pretty much never run over 15psi, 5 being what it's at most of the day.

 

[leashy333]

I have a 10gpd stenner, I'm away from the house so can't check model number now. I have had it for threeish years now, I have found the duckbill style check valve to be worthless... the salt crystals that collect in the bleach tank regularly stick in the duckbill rendering it useless. The true check valve is the rollers pinching the tube off in the pump head. Once I caught my bulk tank slowly filling back up, I thought yea it's the check valve so I pulled it off and sure enough full of chunks. I switched it out and a week later same thing. I dug a little deeper and did some research, turns out my tube was worn letting water flow back through it. Replaced that tube a little over a year ago and no problems since. First one lasted two years.

I have the stenner plumbed into my empty inline puck chlorination. I use a VS pump that I pretty much never run over 15psi, 5 being what it's at most of the day.

Interesting, so the pressure from the water was enough to cause a backflow in a worn out stenner tube causing your bleach tank to slowly fill with water. I guess that confirms my route then of just having it drip into the water rather than injecting it into my return line Seems that would be the most trouble free.

By the way, stenner told me not to use the the check valve with the duckbill unless the pressure is at least 25 psi. They said it takes that much pressure to open that duckbill or something along those lines. And that if the pressure is lower like it would be with a typical pool, the tube will get worn out faster because its having to push harder to open the check valve. In other words, sounds like the tube will have too much pressure on it causing it to wear out or fail sooner. Sounds like that could make sense. So yeah, they recommended the injection valve instead.

 

[Topher55]

Good to know on the pressure and duckbill. Maybe that contributed to mine wearing out. I might pull it off and see what happens.

And if I had a good way to inject directly to the pool that's what I would do.

 

[leashy333]

Good to know on the pressure and duckbill. Maybe that contributed to mine wearing out. I might pull it off and see what happens.

And if I had a good way to inject directly to the pool that's what I would do.

Maybe it could have, though it seems you got some good use out of it. Supposedly you're supposed to replace it every year, but I'll probably just see how long mine lasts. They talked me into buying #1 tube, which has a max of 3 gallons per day vs 10 gallons a day like the #2 tube (the tube is skinnier). But I wonder if I should have just gone with a #2 and just put the pump a timer so it runs less time. Seems it would be less wear and tear on the pump. Mine is the adjustable rate pump and I'm also wondering if it would be better to run it on a timer on full speed than on a lower speed. When i saw how the pump operates on a lower speed - it seems less than ideal if you want the pump to last a long time....it basically cuts the rollers on and off rather than just running at a lower speed. Seems that years of doing that would end in a shorter life for the pump, but maybe I'm wrong.

 

[Topher55]

When I bought mine I figured the 10 gpd pump would have to run less and extend its life. I use a digital Christmas light timer and can control run time to the minute. So plenty of "adjustability" there. I'm pretty sure I have the #2 tube.

 

[leashy333]

I'm guessing you time it to run more in the heat of the summer? It seems like our manual chlorine additions are on a bell curve, with low additions in May, starting to up it in June, full amount in July/August, and then back down some to close out the season. Of course, all having to do with the water temp and sunlight.

 

[Topher55]

Yes it's the longer days, and in my case the sun is higher in the sky which causes it to clear a tree line resulting in even more direct sunlight.

My summer consumption is over twice my late fall and winter. When the water gets cold and no one is swimming I barely stay at minimum FC. When the bather load is high I shoot for the higher end of the recommended level.

Basically what I do is test once or twice a week if FC is off I'll adjust the timer. I know using 10% that about 40 minutes of run time is 1ppm FC. I use that info to make the timer adjustment. then I'll test the next day and adjust if necessary. when I get it where I want it I'll go back to weekly testing. If we have a party (high bather load) then I'll just manually dose it because that's more of a one time thing, not something I want to adjust my automated dosing to.