New Member Post - Initial Info and Issue

Mr Bruce · Jun 1, 2015

Here's what ABCs says:

CH - Calcium Hardness

Calcium hardness indicates the amount of calcium in the water. Over time, water with low calcium levels will tend to dissolve calcium out of plaster, pebble, tile, stone, concrete, and to some extent fiberglass surfaces. You can prevent this from happening by keeping the water saturated with calcium. In a vinyl liner pool there is no need for calcium, though high levels can still cause problems. A plaster pool should have CH levels between 250 and 350 if possible. Calcium helps fiberglass pools resist staining and cobalt spotting. If you have a spa you might want to keep CH at at least 100 to 150 to reduce foaming.

You increase CH with calcium chloride, sold as a deicer and by pool stores, or calcium chloride dihydrate, sold by pools stores for increasing calcium. You lower calcium by replacing water or using a reverse osmosis water treatment.

Again I should defer to the more knowledgeable members of the forum but I am under the impression that OCLT passing trumps worrying about CH. I think it is a problem only if the water is cloudy but again I'm not sure. Hopefully someone will be along shortly.

cramol · Jun 2, 2015

I did see that CH for a fiberglass pool was beneficial but I didn't see an acceptable range and I have a pretty high reading. I know I read somewhere that high levels are not good for a heater which is why I decided to reduce my levels. After my partial replacement my CH fell to 475. Not as low as i wanted but close enough at this point until I can figure out the ideal range for my setup.

I vacuumed and cleaned out the cartridges and put 60 oz of HTH CYA in two socks (I needed two because i could not find anything taller than ankle length anywhere in my house .... where are you 1985 when I need you???) Anyway, at that point i decided to start my SLAM in order to reduce my CC. The goal was to get up to the CYA 30 shock level of 12 .... not sure what happened but it climbed to 16.5 ppm. I followed pool math but maybe I had an input error that I overlooked. However I don't think an FC that high is dangerous as long as nobody swims. My CC was 4.0. Both readings were taken at 10:00pm

This morning I tested again around 6:30am and my FC was almost at the same level. It came in at 16.0. CC appeared to be down slightly as well to 3.75. My water is super clear, my drop over night was only 0.5. I think at this point my goal is to just keep the SLAM going until CC is down to 0, right? As far as CYA testing is concerned, can I assumed that once the socks are empty that the product has completely been consumed by the water? Is it only when you add directly to the skimmer basket that you have to wait a week since it may get caught up in your filter? I'm trying not to test CYA daily because I may run out of that testing solution pretty quickly.

wantmoore · Jun 2, 2015

cramol said:
This morning I tested again around 6:30am and my FC was almost at the same level. It came in at 16.0. CC appeared to be down slightly as well to 3.75. My water is super clear, my drop over night was only 0.5. I think at this point my goal is to just keep the SLAM going until CC is down to 0, right? As far as CYA testing is concerned, can I assumed that once the socks are empty that the product has completely been consumed by the water? Is it only when you add directly to the skimmer basket that you have to wait a week since it may get caught up in your filter? I'm trying not to test CYA daily because I may run out of that testing solution pretty quickly.

Even though the sock is empty, it can take up to a week for the increased CYA to show up on your test. For now, assume that what you added is there for purposes of your SLAM then re-test in a week or so and adjust if needed.

cramol · Jun 3, 2015

Since I can only add bleach in the morning and evening due to my work schedule, to keep my slam going should I add enough bleach to exceed my shock level in the morning so that it does not drop below it throughout the day? Is there any downside to that (other than using more bleach than needed)?

chiefwej · Jun 3, 2015

If you are doing a SLAM and won't be there to closely monitor FC level you can use PoolMath to safely raise it to the area of "Mustard Algae Shock Level". It listed down at the bottom of the chart.

Also, check your bleach setting on PoolMath. You seem to be overshooting your target FC. Do you have the bleach strength set at 6% or 8 1/2%?

During a SLAM, if the water is clear and the FC is at or below "Shock Level" (per PoolMath) it is safe to swim. You don't have to drop the FC level way down, and lose ground to use the pool.

As far as your CH level, I would love to have my pool read 500. My fill water reads in the 350+ range, and with desert heat and ridiculous evaporation rates, it very quickly rises to extreme levels. I've spent an entire summer managing my pool with a CH over 1,000. What's important is not the CH but the CSI. CH tells you how much calcium is present in the water. CSI tells you if that calcium will deposit on surfaces as scale, or if the water will become corrosive and dissolve and draw calcium out of the pool shell. If you are diligent about watching pH and resulting CSI level, you can manage high CH. At very high levels it does become more of a "tight-rope act", but it can be done. The levels you have are not problematic.

cramol · Jun 4, 2015

Thanks chiefwej. I wasn't aware of the CSI reading. I must have missed that part of the Pool School. According to the calculations my reading is definitely in check. Last night from 7pm until this morning at 6:30 am I didn't lose any FC at all. First time that has happened. I suspect that maybe the addition of CYA had something to do with it (unless of course that only applies to FC loss due to the sun). My CC keeps dropping as well and is down to 2.5. I feel better about my CH now and probably ended up wasting money on a partial refill but I guess you live and learn. It would definitely be a challenging set up in your region and the CH of your fill water ..... however I won't feel too bad for you because I'd much rather be dealing with keeping my water chemistry in check in January than looking at a blanket of snow covering my pool

I feel as if I'm pretty close to a true balance. Once I get my CC to disappear I should be good to go. Everything else seems to be in order. I look forward to the next challenge of trying to come up with a perfect solution of how much bleach to add based on temps, sun, and pool activity.

chiefwej · Jun 4, 2015

All your chemical additions should be very precisely calculated using the PoolMath application. Just be sure that you have the correct volume for your pool, the correct concentrations for all chemicals, then you put in your test results and it does its magic. I've always found it to be very accurate. It also gives you that very important CSI result.