Will improperly charging a chlorine feeder affect Cl levels?

[Tcraw487]

Hey all,

So I've been scratching my head at this for a while and can't seem to identify the problem with my low chlorine levels. I've tested the water myself and taken it to a local shop and everything seems to be in normal ranges minus the chlorine. I learned that I wasn't properly charging our Pentair chlorine filter after replacing tablets and was wondering if that could affect it? I followed the directions this morning and am hoping to test this afternoon and see a higher level.

Any input would be greatly appreciated!



16k gallon in-ground vinyl
Sand Filter
Pentair auto Cl feeder

 

[RobbieH]

Here's my guess:

You've been using tablets for a long time. CYA has gone sky-high and now your chlorine is no longer effective. Because of that, you now have some algae in your pool, which is consuming the chlorine.

A full set of test results would be great, but I suspect CYA of well over 100.

 

[Tcraw487]

Thanks for the reply! I'm conveniently headed to the shop to buy more algaecide today (used the last bit when opening) so I'll run a water sample by there and get a full work up.

 

[RobbieH]

OK, we do not typically recommend algeacide. So, you are at a fork in the road. You'll either have to follow the pool store's recommendations or follow the methods we use here. The two will not work together.

Read through this, but we really need a full set of test results.
Pool School - SLAM - Shock Level And Maintain

I recommend getting your own test kit, and highly recommend the TF-100.
TFTestkits.net
Pool stores are notorious for doing the tests wrong, and even worse selling you stuff you don't need, and worse than that selling you products that make matters worse.

The pool store will sell you a Taylor K2005 which does not include the FAS-DPD test you need to SLAM your pool.

EDIT: Making matters worse - they will probably sell you a bunch of "shock" product, which will most likely drive your CYA up even higher.

 

[Tcraw487]

Glad I checked my phone before buying that! I did bring a sample of water in and my CYA was at 60. I did mention that we had 4 tablets in our feeder and that it hadn't changed in 2 weeks. Guy at the store (who has been helpful and upfront so far IMO) suspects we might have a bad control valve coming from the feeder. He gave me a new one to go install and see if that helped over the weekend and if not he said just to bring it back free of charge. I'm hoping that'll fix the problem and then I can start reading up on SLAM.