Can you maintain a stable CYA and use an inline chlorinator?

[TomC]

Ok, at the risk of being the opinion which goes against the flow of this board, I use an inline chlorinator with the 3 inch trichlor tabs. I think it's a Pentair Rainbow 320, it fits about 11 tabs at a time. I do it for convenience and the fact that it's within my comfort zone since I've maintained pools this way since I was about 14. I shock with bleach, but maintain my FC residual with the tabs. By the end of the season my CYA is approaching 65-70 ppm. My water ( after the initial clean up ) is always crystal clear.

My pool gets a lot of use, so there is a lot of splash out, and it's pretty windy, so I get a lot of evaporation. The only downside of using the chlorinator with the trichlor tabs, for me, is that the ph will drift downwards as the season progresses, so I always have baking soda and borax in the shed to stabilize and raise the ph.

I've never admitted this on this forum before, because I feel like an idiot, but.....when I open my pool at the end of May, my CYA is gone. I don't know why or how but it's pretty much at zero. So I never have an issue with my CYA being too high.

I see that you're in Tampa, so you probably never close your pool. So whatever strange alchemy occurs in my pool over the winter to degrade my CYA won't happen in yours. I think if I were in your position and based on the size of your pool, I would chlorinate with bleach and use the trichlor tabs when away on vacation. Good luck!

Tom

[BigDave]

@TomC: I don't think anyone here is opposed to trichlor or inline feeders. The issue is that trichlor adds 6ppm CYA for every 10ppm FC and you have to increase target FC as CYA increases. This can be a little hard to grasp, setting a CYA level and maintaing the matching FC is eaisier to teach. A common trichlor scenario is the Green August Pool. A great many pools turn green late in the summer because thier owners are trying to maintain a FC level that's too low for the CYA that's built up.

Your experience of losing CYA over the winter is also common. There are bacteria that consume CYA and release nitrogen compounds sometimes as ammonia. This CYA consumption can happen quite quickly once FC is depleted and the bacteria is allowed to grow. You may or may not have observed that sometimes it take alot - ALOT of chlorine before chlorine will hold in the spring. This is often the result of ammonia formation.

[TomC]

Thanks Dave, that explains it then.

Tom