Maintaining FC in a new Salt System

[ohlsonfamily4]

We switched our pool upon opening(May) to a SWG and have had issues ALL summer keeping chlorine levels up. I firstly have to admit I only have dip sticks from my local pool store to test at home, but those and the store readings for my cya have always read WNL. We have found that atlas every two weeks we have had to add 2-3 bags of "calcium Hypochlorite" based shock to bring level back up then it seems to dwindle back down. We have had a very sunny summer here in the north east but I still feel like the chlorine is just evaporating for lack of any better term. I was told by my pool store after the levels must have stayed low to long and pool was green despite two rounds of shock(3 bags each time) 3 days apart that I had a chlorine lock. each time I have gone in to get more shock(when dip stick reads virtually no detectable chlorine) he tells me "must be another chlorine lock". I feel like I have spent more in chlorine shock this summer then just using my old chlorinator. I am looking for a few tips on how to solve this issue. I should also add the pool clarity will cloud up slightly and i will notice a green film on my liner walls when levels get too low. My pump runs from 8am to 8pm and recently I had turned down my % on the SWG to 50% bc I thought this was related to the salt level reading on my generator (3200) however I am learning through these threads that it isn't true. We also have been in the habit most weeks to super chlorinate for a 24 hour period.
Any thoughts on what I should have been doing all season (we are approaching closing in 2-3 weeks)
Knowing I probably have an algae problem do I need to change my closing or just close and deal with it next year?

Pool Reading Earlier tonight (before 3 bags of shock)
FC <0.5
ALK 100
pH 7.2-7.8
CyA 80

I know theres a lot of information requested here so thank you in advance! I have spent the last 3 hours reading through forums and have felt so lost all summer and feeling like I finally could get some real ones. The pool store manager just keeps telling me "I don't know why you keep having a chlorine lock"

 

[jblizzle]

You have been gone for 2 years
Sounds like it is now time to learn what we teach

First, stop going to the pool store. If you want to take control, you need to ditch the test strips and pool store testing and invest in one of the Recommended Test Kits. Once you can post a full set of reliable test results, then we can get you started on the path to an enjoyable pool.

The first thing I would do would be raise the FC with bleach and Perform the Overnight Chlorine Loss Test to find out if there is something lurking in the pool. If you fail or see algae anywhere, then you need to follow the ShockLevelAndMAINTAIN Process. After passing that, you can then get the SWG dialed in to maintain adequate FC levels (which are a function of your CYA level according to the FC/CYA Chart ... bet the pool store did not tell you that, since they are unable to grasp that connection even though it has been know since the 1970s ... or maybe they ignore it to continue to like their pocket$)

Have you discovered Pool School yet? Start with these:
ABCs of Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool

 

[YippeeSkippy]

Oh my...where to begin?? I'm going to be blunt-Your pool store is clueless and you've been led wrong.

FIrst off- with a vinyl pool you don't *need* to be adding calcium. If you need to clear up algae you need liquid chlorine and only liquid chlorine. You can buy it at many pool stores (usually 12.5%) or at the local grocery store (8.25% regular plain bleach). Killing algae is a process, not a "once or twice toss a bag of product in" because algae has to be worn down and beaten by keeping the FC up consistently for as much time as it needs to not be still reproducing or hiding. Algae hides in light niches, under ladders, in areas with poor circulation and also makes its own protective covering (biofilm) which shields it from chlorine. That's why you have to brush often to disrupt any possible biofilm and test often to maintain that FC level up. Testing and treating even hourly will yield the fastest results in clearing your water.

Your SWG *may* be undersized for your pool, could be fine sized and working well but can't keep up against the algae reproduction. WHen ever you doubt it working or want to boost your FC- go ahead and just use liquid chlorine to cover your needs while you research the problem.

What size and make is your SWG? How many gallons is your pool?

Where is YOUR test kit??? Pool stores are notorious for getting inaccurate test results, seriously. You need to take charge of your pool and test yourself. Your interest in quality results doesn't cost you an arm and a leg in unnecessary pool store products.

Go hit PoolSchool up at the top right side of this website and soak up all the learnin'

Holler back...

 

[ohlsonfamily4]

Thank You both for taking the time to respond. I had discovered the "Pool School" and thank you for the specific areas you pointed out. I plan on doing some more reading tonight in those areas, purchasing a recommended kit then will perform the overnight chlorine loss test and post some results when my kit comes in.
Thanks Again!!!!

 

[jblizzle]

Well really since you have had very low FC levels and have seen algae, there is really no point in doing the OCLT at this point. You need to follow the SLAM process and then start dealing with the SWG with a clean slate.

 

[chiefwej]

When ordering a test kit, the TF-100 can't be beat and since you already have a potential issue with algae, you should go for the XL option. That gives you more of the reagents you will be using fighting algae during a SLAM. The SpeedStir makes testing so much quicker and more accurate.

Both of these are things I had to learn the hard way, when I had to go back and order more reagents and added the SpeedStir to my kit.