Stenner Troubles

[spoonman]

Hi folks. I’m using a Stenner for chlorine Automation. It was working well for a while, but since summer has come I can’t seem to keep up with chlorine demand. I’ve tripled the run time, insulated the fed tubes, and have verified that chlorine is in fact feeding from the supply tube.Yesterday afternoon I checked by chlorine level and had about 6ppm. This morning I had a similar reading but the Stenner was supposed to add 3ppm overnight. I’m getting tired of tinkering around with this thing and am hoping someone here will have some ideas or suggestions that I may not have considered.

 

[griffths]

A few things come to mind

You have sometthng in your pool using more chlorine that in the past. Perform a overnite chlorine loss test to verify.
What are your current test results? Specificslly your CYA level. Maybe it has dropped since you last tested.
Is os possible you have inadvertently installed a smaller pump tube that you previously had in the pump?
I would suggest you check actual output volume of pump vs expected to confirm pUmp is operating properly.
It may be that daily chlorine loss is just higher due to hotter weather and/or more sun than beforr.
Are you using a weaker concentration of bleach or is your bleach old and weaker than before

 

[joshua5438]

Above is all I can think of also. Once you confirm the overnight test and confirm your pump is actually pumping the amount you think maybe we can start searching other possible issues. I had a similar issue this year and thought I had a clog in the stenner line. Blew everything out with compressed air and thought it was good. Started having the same issue again a few weeks later and finally found I had a bad ferrule insert. It had became creased at some point when I was switching out hoses and causing air to get into the system. So it was pumping exactly half the rate it was supposed to be.

 

[Steve_in_C]

You should turn you pool pump on for agitation and recheck your Stenner (re calibrate). Do this all after dark and recheck your FC about 30 m after your Stenner stops to see what it's putting in. The you can see how much it drops the rest of the night. If your pump is working properly, you can cut it completely off and to an OCLT the next night using manual chlorine additions. It will likely be easier to troubleshoot problems with manual additions. Solve the problem, and then turn Stenner back on for maintenance.

 

[Dirk]

I'd look at chlorine expiration, as griffths mentions. The higher strength you started with (10%? 12.5%) the quicker it will degrade. How long has it been in the tank? Is the tank in the sun? Even if you started with very fresh chlorine, it could have been degraded to begin with (like if the store left the pallet out in the sun for a while). And it your tank has been out in the sun, I think chlorine could degrade quite quickly.

Depending on what you want to start troubleshooting first, one of the things to try is to empty the tank and replace with known fresh chlorine. If that was the problem, you could put less in the tank at a time, and store the rest in a cool place somewhere, or use 6% bleach, as I've read the lower the strength the better it holds up...

 

[Steve_in_C]

The reason I use 6% bleach

 

[spoonman]

I checked tested the dosing and the Stenner pump is dosing the correct amount according to specifications. I also wrapped my tubing to ensure that there is no sunlight degradation. FYI, my tank is also UV resistant.

According to everyone's feedback, it seems like there are 3 remaining possibilities why the correct amount of chlorine isn't getting into the pool...

1. Back-pressure from pool pump. I'm not sure if this is valid. Could my pool pump pressure be enough to counteract the Stenner's flow?
2. Chlorine degradation (thanks Steve in C). This could be the culprit. I live in Phoenix and it is summer. Yes, my Stenner tank is UV protected, but the chlorine tank is in the sun and the chlorine itself is probably 100+ degrees.
3. Chlorine is getting into pool, but is being used up (algae?).

It sounds like I should test the chlorine before/after running the pump as a next step. This would eliminate #1 and #2.

 

[rphpool]

I put my tank inside of a garbage can and cover, helps keep it cooler