Keeping my fountain water clear

[kma_97]

Hi All,

I have a fountain (~660 Gal). Water started turning greenish. Not too bad yet, but it’s different from what it normally is (crystal clear):



What’s the best course of action to get it and keep it clear, given that I am not concerned with it being swimmable, not irritating eyes, etc? Just pour liquid chlorine? Use chlorine tabs? Either, neither, something else?

Thank you!

 

[mknauss]

If it normally is crystal clear, what do you do to keep it that way? Do you have lots of drain refill of the fountain?

 

[JoyfulNoise]

Is it just a pump and a fountain? Is there any filtration? Please post more information about it and how you normally care for it.

 

[kma_97]

If it normally is crystal clear, what do you do to keep it that way? Do you have lots of drain refill of the fountain?

Previous owner would shock it as it started turning greenish. My former pool pro advised against it and just kept a few chlorine tabs at the bottom in the corner. Not sure what else he was adding…
I don’t normally drain it. I’ve installed a float valve on an old fill line (previous owner used a hose) and as the water evaporates, it adds as needed.

 

[kma_97]

Is it just a pump and a fountain? Is there any filtration? Please post more information about it and how you normally care for it.

Just a pump and a fountain. No filter. Previous owner would shock it as it started turning greenish. My former pool pro advised against it and just kept a few chlorine tabs at the bottom in the corner. Not sure what else he was adding…

 

[mknauss]

Continue doing the chlorine tabs. But you need to dump about half the volume every month. Or the CYA will go way too high, which is likely what you have now.

To clear what you have , dump it, clean with some chlorine, and start over.

 

[kma_97]

Continue doing the chlorine tabs. But you need to dump about half the volume every month. Or the CYA will go way too high, which is likely what you have now.

To clear what you have , dump it, clean with some chlorine, and start over.

Got it! Thank you!

 

[JoyfulNoise]

I suggest adding using an algaecide and actually avoid using tablets. Dose with Dichlor powder instead and then switch over to liquid chlorine. One 8oz trichlor tab will raise the CYA to 51ppm. That’s already too high. Honestly, if no one is using it as a pool, a copper based algaecide will keep it from turning green. You just need to keep the chlorine at a low level (1-2 ppm) and the CYA around 30ppm. You also need to keep the pH at 7.5 or lower.

Use a chelated copper algaecide and add no more than the amount necessary to get you 0.3 to 0.5ppm. You could also add straight copper sulfate if you can find it.

If you don’t want to use copper then use PolyQuat-60 algaecide. Avoid linear quat algaecides as they will just cause foaminess.