No CYA and algae at opening

nadar

Active member
Oct 21, 2018
33
Northern Tennessee
We had a wetter than normal winter and had to drain water out of our mesh-covered pool several times in order to keep the water level below the tile line. We opened up our pool yesterday and it was much greener than usual and there was no CYA in our pool. All of the rain also severely lowered our calcium level and salt level. I had a bottle of Natural Chemistry's Liquid Conditioner in my utility room that I bought last fall and added that to my pool. If my CYA level is truly 0 like the test seems to indicate, the liquid conditioner should have got the level to 19 according to the pool math calculator. I retested the CYA level a few hours after adding the liquid CYA and I still see the dot at the 30 mark so I assume the CYA is still below 30 or it is too soon to test. I'm wondering if it would be okay to start the SLAM tonight even though my CYA is probably still slightly below 30, or if I should SLAM it a few times with Dichlor instead of bleach which will add some CYA to the pool. I'm going to have to get my CYA level up to at least 60 eventually since I have a SWG, but I just want to get the level to 30 right now so I can do the SLAM.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
29,270
Laughlin, NV
Can you post all your test results? Especially the FC and CC.
Do not add any more CYA yet until we get that information.
 

nadar

Active member
Oct 21, 2018
33
Northern Tennessee
Can you post all your test results? Especially the FC and CC.
Do not add any more CYA yet until we get that information.
Here are our latest test results.
FC - 4
CC - 1 (or maybe .5)
PH - 7.4 or 7.6
TA - 60
calcium - 140
CYA - 0
(We have added chlorine several times today and it appears to be holding chlorine fairly well, considering the fact that it has no CYA and algae.)
 
Last edited:

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
29,270
Laughlin, NV
OK -- just wanted to see if you needed to check for ammonia. If you feel the chlorine is not getting immediately consumed, then go ahead with your SLAM. Take FC to 10 and maintain. When you can, get more CYA and add 10 ppm worth via the sock method. Once you start that, assume you have 30 ppm CYA and use FC of 12.
 

nadar

Active member
Oct 21, 2018
33
Northern Tennessee
OK -- just wanted to see if you needed to check for ammonia. If you feel the chlorine is not getting immediately consumed, then go ahead with your SLAM. Take FC to 10 and maintain. When you can, get more CYA and add 10 ppm worth via the sock method. Once you start that, assume you have 30 ppm CYA and use FC of 12.
Thanks so much for the advice. I'm curious to know why you recommend that I increase the CYA with granular CYA in a sock instead of using Dichlor. If the liquid conditioner that I added today got the level to 19 like the pool math calculator indicated, I would only need to add 3 pounds of Dichlor and it would get my level to 30. After I get it to 30, I could do the rest of my chlorine additions with liquid chlorine. Since I'm going to have to backwash this week in order to get rid of the algae, it seems like the granular CYA might not work as well since you aren't supposed to backwash for a week after adding it. I don't personally like to mess with CYA in a sock but I'd be glad to use that method if it would work better though.
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
29,270
Laughlin, NV
If you can use dichlor to get your CYA up quickly enough, that is fine. Just be sure to weigh how much you are using to track where you are.

Since I have never used dichlor, I do not think about it when I respond. It is a more complex process than just using CYA.

Take care.
 

nadar

Active member
Oct 21, 2018
33
Northern Tennessee
If you can use dichlor to get your CYA up quickly enough, that is fine. Just be sure to weigh how much you are using to track where you are.

Since I have never used dichlor, I do not think about it when I respond. It is a more complex process than just using CYA.

Take care.
Thanks so much for all of the advice. I started the SLAM on Saturday night, and my pool has already cleared up! I didn't lose any chlorine overnight and my CC was .5 this morning so I assume I passed the OCLT. There is a black substance on the floor of the pool though that looks like dirt or maybe dead algae. It goes away when I brush it but it clumps back up later. When my pool was cloudy, I thought these clumps were leaves but I can now see that it is actually some kind of dirty substance. After I vacuum this up, should I continue the SLAM until I pass the OCLT again, just in case it is black algae instead of dirt or dead algae? Or would this be overkill since my water is clear and I have already passed the OCLT?
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
29,270
Laughlin, NV
The first criteria of a successful SLAM is Crystal Clear Water. If you have algae/dead algea in the pool, that is not crystal clear water.

Keep at SLAM FC level until all the algae / dead algae is gone and then run your OCLT. Be sure to do a CC test in the morning of the OCLT.