Ammonia at opening. What am I doing wrong at closing?

[Ben_G]

This is the second year in a row that I have had high Ammonia levels when I’ve gone to open my pool (8 PPM Ammonia, 0 FC, 0 CYA). Before closing, I SLAMed the pool and added PolyQuat at the startup level and verified my CYA level, per the Pool School book.

Is there anything else I can do to avoid this in the future? It’s a little aggravating (and expensive) to have to dump 20+ gallons of 12.5% bleach in the pool every spring just to get my FC to go above zero to start a SLAM

 

[ajw22]

Ammonia is caused by bacteria that gets into the pool. The bacteria feasts on CYA and creates the ammonia.

To prevent the ammonia you need to keep the bacteria from getting into the pool while it is closed.

Are you in a rural area where you get runoff from farms or ranches?

 

[Ben_G]

I’m not in a rural area, but the pool is in a wooded yard. Even with the cover on over the winter, plenty of leaves and other organic material makes it into the pool between when I close and when I open.

 

[ajw22]

Look at the grading around the pool and see if you can get water to run away from the pool and minimize what gets in the water.

 

[PoolGate]

Do you let dogs or other animals in the pool?

 

[Leebo]

What does your water look like when you open?

 

[Ben_G]

We do have two dogs, but they don’t go in the pool.
The water has been reasonably clear both years. It’s been a little cloudy, but I’ve still been able to see the main drain in the deep end. It’s never had a hint of green or any other color though.

 

[Ben_G]

I just had another thought. The pool has an automatic cover. Could it be dirt or organic material in the recess where the cover retracts that’s harboring the bacteria? I don’t think I’ve ever really cleaned that out…

 

[ajw22]

I just had another thought. The pool has an automatic cover. Could it be dirt or organic material in the recess where the cover retracts that’s harboring the bacteria? I don’t think I’ve ever really cleaned that out…

If you have stagnant water in there then pour some chlorine in and test it for a FC level.

 

[PoolGate]

No one really knows why the cya bacteria hits or what triggers it. It just happens. That's why I asked about the dogs the other pool I helped recover from CYA bacteria let their filthy dogs in the pool.

 

[Ben_G]

No one really knows why the cya bacteria hits or what triggers it. It just happens. That's why I asked about the dogs the other pool I helped recover from CYA bacteria let their filthy dogs in the pool.

After clearing out all the Ammonia (it only took 17 gallons of 12.5% versus 25 from last years opening. Improvement!) The SLAM itself went pretty quickly and I never had a lot of combined chlorine. I’m guessing that meant the bacteria had done their thing last fall, then starved/froze over the winter.

I thought I had accounted for it, but I just need to make sure I’m extra careful with my pre-close SLAM and water temperature.

 

[YippeeSkippy]

Are you making sure you manage your pool all the way to closing? And only closing once the water gets to 60 or lower?

Maddie