I've always wondered. The tablets I use are mainly Calcium Hypochlorite, as is the pool shock I use. I'm guessing that the calcium ends up in the water forever. I'm not sure if this is a major source of water hardness, but I'm curious...
Do tablets add to water hardness
- Thread starter Rszimm
- Start date
Ooops. The tablets I use are actually Trichloro-S-Triazinetrione, so I'm guessing no calcium? The shock is indeed Calcium Hypochlorite, so the question still stands (albeit I only shock maybe once a week and only in the summer.)
- May 3, 2014
- 58,605
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
With the high calcium in most tap water in the southwest, Cal Hypo should be banned.
Yes, it is adding calcium.
And there is no reason to 'shock' a pool. See
Yes, it is adding calcium.
And there is no reason to 'shock' a pool. See
- Sep 23, 2015
- 1,594
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V25
And the tablets are leaving behind cyanuric acid and driving you CYA up. Do you know what your current CYA and CH levels are?
Well, I'm just refilling the pool now, so CYA levels are zero. However, my CYA usually stays normal to low. It's a saltwater pool usually, so I don't really use the tablets much. I might throw a few in a floater during the winter months.
My CH hardness levels were insanely high before I drained the pool. I guess I'll pitch the rest of my Cal Hypo shock and get something without calcium. I have had problems with black algae that the cal-hypo tends to work well for. I'll drop some in a black algae area, let it settle to the bottom where the algae stain is, let it sit about 5 minutes, and then scrub. The algae not only dies, but the spot bleaches out (or the scrubbing gets it off)...
My CH hardness levels were insanely high before I drained the pool. I guess I'll pitch the rest of my Cal Hypo shock and get something without calcium. I have had problems with black algae that the cal-hypo tends to work well for. I'll drop some in a black algae area, let it settle to the bottom where the algae stain is, let it sit about 5 minutes, and then scrub. The algae not only dies, but the spot bleaches out (or the scrubbing gets it off)...
Just watched your video. So I guess I'll go get some liquid chlorine rather than the granules, and stop with the weekly shocks..... I will say that in the height of the summer I've really struggled to keep my chlorine levels up with the SWG alone.
- May 3, 2014
- 58,605
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
Your IC40 should generate plenty of chlorine. Keeping your CYA at 80 or even 90 during July and August can help.
- May 3, 2014
- 58,605
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
CYA at our pool water temperatures and UV levels degrades by up to 10 or even 15 ppm per month from June to September. Keeping the CYA elevated during the peak UV months helps retain FC levels. If my CYA drops to 70 or below, the FC usage spikes by several ppm per day. At 80 ppm CYA, my FC loss normally is no more than 4 or 5 ppm per day.
- May 3, 2014
- 58,605
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
- Sep 23, 2015
- 1,594
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V25
I’ve saw a bit of black algae towards the end of summer last season in one of my pools. I brushed it, increased my minimum FC a little but basically left it till the end of the season. Come autumn I SLAM’ed when the the water was to cold swim.
But the real treatment is prevention. The black algae took hold because my target FC dipped to low a few times. I now treat 5ppm FC as my absolute minimum with a CYA of 70ppm. Ive always been a bit conservative with the CYA but may start to dose my CYA to 80ppm beginning to mid summer. But remember, when your CYA is up at 70-80ppm there is no pucks or dried chlorinated products of any kind.
You have invested quite a bit in your pool, it is quite high end with all the waterfalls and in floor cleaning, have you considered a water softener to pretreat you top up water? I’m assuming your tap water has high CH, have you tested it?
Water softening is on the agenda. Just been too busy lately. Our water is hard. 250 mg/L with over 500 TDS. I also have plans for a rainwater supply system for the pool. Most of the plumbing is in, but it needs some finishing touches. All on the to-do list!
I’m not sure what I have is black algae. From everyone’s pictures it would seem it should be splotchy. Mine is more of an overall blackness on the walls and floor. Sort of like what you get with green algae, but black. It’s got an amazingly tenacious bond to the surface
I’m not sure what I have is black algae. From everyone’s pictures it would seem it should be splotchy. Mine is more of an overall blackness on the walls and floor. Sort of like what you get with green algae, but black. It’s got an amazingly tenacious bond to the surface