New to the forum and in need of assistance

[aylad]

Hello, Tideman, and welcome to the forum!!

Your first order of business should be to remove anymore trichlor pucks you have in the chlorinator. They do help feed chlorine into the pool, but they also drive pH down (probably why yours is so low but will probably come up on its own after switching to a different chlorine source) and drives CYA high. If you couldn't see the black dot after about 1/2 inch, then your CYA is well above 100, and possibly nearing 200, which is why you're having recurrent algae blooms. Where most people get into trouble with the chlorinators is that they don't understand that as CYA climbs, so must your baseline chlorine levels to make sure that algae doesn't grow. The chlorine level you must attain to reach "shock" level also climbs along with your CYA. IN short, the trichlor use has gotten your CYA out of control, which is causing your problems, so the trichlor needs to go, at least for the rest of this season.

So..you have a decision to make. With your CYA as high as it is, you're going to have to elevate your chlorine to the 25-30 ppm range and sustain that level for as long as it takes for the algae to truly die, as evidenced by clear water, combined chlorine less than 0.5, AND not losing any chlorine when measuring at sundown and again at sunup. This can take several days, and lots and LOTS of bleach. When you do finally get the algae defeated, you're going to have to run your pool at 8-12 ppm of chlorine ALL THE TIME to keep the algae from coming back. I don't know how much more swim time you have, or how feasible it is to drain/replace some water, but the pool will be much easier to clear up and maintain if you can drain/refill 50% or so of the water to bring that CYA down to a manageable level. THen your shock level that you must maintain to clear the algae and the minimum chlorine levels you have to maintain afterward will both be much lower and easier to manage. Just for a point of reference, in a pool your size, it's going to take about 7 1/2 gallons of 6% bleach to attain "shock" level, and will take about 1 quart to raise your chlorine by 1 ppm when calculating how much more to add each time to get back up to that 25 ppm level.

Your calcium level is very high, also--do you have high calcium in your fill water, or is it a result of using cal-hypo to shock? Doing a partial drain/refill will also help get that number down, if it's a result of cal-hypo use. It's high enough that any added calcium can create problems with milky water, which would eliminate cal-hypo as a chlorine source for you if you choose not to drain/refill some water.

Whether you choose to drain/refill or try to manage it the way it is, is up to you, and we'll be glad to help walk you through it, but either way I very very strongly recommend that you switch to bleach (or liquid chlorine, if it's available to you) for your chlorine source at least for the rest of this season. It will assist you in clearing up the pool, but not affect your pH like trichlor, or your CYA or CH like trichlor or cal-hypo will.

You can safely return the CYA to the store, if they'll take it back, as well as the baking soda, unless you'll use it otherwise around the house. (I would see if they'll trade it for liquid chlorine!!) Any CYA addition you need to make in future seasons can happen via your leftover trichlor, and the baking soda is used to raise alk--and yours is high enough.

Let us know what you decide, and we'll all go from there. Again, welcome to the forum, and congratulations on taking control of your own pool!!

Janet