Unable to maintain chlorine levels - help

[Teald024]

Questions - through the SLAM process do i need to re-check my CYA at some point to make sure i'm maintaining the right FC shock level? I have calcium hypo-chlorite 73%; is it ok to use this or should i stick with household bleach (6 or 8.25 %)? once i have not lost more than 1 ppm overnight, my CC is .5 and water is clear what do i do then? i.e. do i turn my in-line chlorinator back on? And, if so, what setting on a 5 dial? Or, should i just continue to maintain FC with household bleach?

Hello and Welcome to TFP!

You do not need to recheck the CYA level. The only thing that will change CYA is drastic changes/ replacement in water. As an example, 10% water change is about 10% change in CYA. You usually don't exchange that much water during a SLAM to worry about it.

Continue to use plain, unscented bleach to add FC. This is the best method.

It's likely too early to do a OCLT. But once you pass the 3 criteria to end the SLAM, then you go into the daily maintenance mode. You can let the FC naturally drift down. Maintain FC per the CYA Chlorine Chart ( link in my sig). We recommend not using the inline chlorinator, but instead use the bleach. If you use the solid chlorine tabs, you just add unneeded CYA again. You could use up the Cal-Hypo if you pay close attention to and keep the CSI below 0.3 so you don't have scaling issues.

 

[mknauss]

If you feel you have exchanged at least 20% of your water you should check the CYA. That is alot of water. So up to you.

You can use the cal hypo if you wish. It adds calcium. Which can be a problem if your CH rises and your CSI goes positive. I would personally stay with bleach.

As soon as you have been in SLAM mode for a few days and your FC is holding between tests, you can do a OCLT Pool School - Perform the Overnight FC Loss Test (OCLT)

No need to test your CC right now. Really does not matter until you do a OCLT

Unless you want your CYA to go back up and algae to return, you need to use bleach for your daily chlorine needs. Keep the pucks for when you will be out of town for a few days.

Good luck.

 

[sas90]

thanks to both of you! this morning my FC is only 9.5 so i will continue to SLAM. I was reading on TFPs site about the different types of algae and i'm very concerned I may have the mustard algae. how would i know for sure? it looks like all of this will be for nothing if it is mustard algae and i don't do it to the extra high mustard algae shock level?

so, if you recall in my 1st post on this issue, i have had green discoloration areas (3-5 inches in diameter; if i didn't act on it of course it was worse and became a continuation around the pool surface on the sides (anywhere from top to bottom on the sides). it brushes off easily, does not cause any cloudiness to the water but with my lack of chlorine issues, it would return at some point. actually, just before i started the SLAM process it had reappeared.
since i started this process, most of it has gone away; however, this morning i did find two very small areas (a few inches in size) with a green discoloration on the sides of my pool. i was planning to brush several times again today and will concentrate on those areas i can see.

It indicates mustard algae is primarily found on the walls on the shaded sides and floor of the pool. however, my pool is on the west side of the house; and at one time or another these green areas have been on all sides of the pool. This morning, the two spots i found most easily were on the southwest and west sides of the pool surface. I don't believe i've seen it on the floor but i do run my vacuum quite a bit. again, my actual water has not been green or even cloudy this season.

any thoughts?

 

[domct203]

The SLAM process is the same regardless of algae type. When mustard algae is suspected, after you pass all three criteria to end the SLAM you raise FC to mustard algae shock level for 24 hours only.

More here:
Pool School - Mustard Algae

 

[sas90]

Hello!
my backyard has an odor of chlorine now. I assume that's normal during the SLAM process?
And others have said it's safe for us to swim during this process, just want to confirm that?
Thank you

 

[mknauss]

You are smelling CC's. That is the by-product of the FC killing algae. The sun burns it off.

You are safe to swim if your FC is at or below your shock level; you can see the bottom of the deep end; and your pH is between 7.2 and 7.8.

Please fill out a signature -- Pool School - Read This BEFORE You Post

Take care.

 

[rfra0525]

is it okay to use bleach in a pool with a colored plaster finish?

 

[mknauss]

Yes. You are using chlorine now are you not?

 

[sas90]

Thank you for the reply
And I'm not sure why my signature dropped off? It's still seen under my profile.
I thought during SLAM ph levels are impacted so not to check them. I'll do that. the FC has been below shock level

 

[mknauss]

You started the SLAM with a pH of 7.2, right? A SLAM does not effect pH anymore than your natural pH rise due to aeration or fill water.

There is no need to test pH during a SLAM, it is inaccurate above FC of 10 ppm.

- - - Updated - - -

Your signature shows now. Might be a mobile vs computer thing.

 

[sas90]

My ph was 7.6 when I started the SLAM. This will be day 3; when I checked my FC last evening it was 10 so I added more bleach to the recommended FC shock level.

- - - Updated - - -

I saw my signature dropped off again so trying to add it here

 

[sas90]

Update - yesterday evening, I added bleach based on required amount from pool math; two hours later (9pm), my FC was 20 (i felt pretty good because this was the first time there wasn't a drop in FC in 2 hours; earlier that day it dropped anywhere from 1-3 ppm every 2 hours). This morning (SLAM Day 4) my FC is 13.5. UGH! I've read there's no formula for how long SLAM takes but does anyone know the average # days? Yesterday, i started monitoring it approximately every 2 hours during daylight hours (although I believe the SLAM process says no less than twice/day so i'm definitely doing more than). Day 1 and 2, I probably monitored/added about 4-5 times each day and had bigger drops in FC thereby adding more bleach at one time. And of course each day i brush all surfaces at least 3 times if not more and run my vacuum almost constantly.

 

[mknauss]

You are doing great. Now it takes POP (pool owner patience).

SLAM takes a few days (easy) to weeks (swamp). You are in between.

Stay at it.

Take care.

 

[pabeader]

You are at the stage where taking pics and posting them is very important, for you and us. Sometimes the changes are small and it's easier to see them when comparing pics.

 

[sas90]

ok - thanks to both! i'm hoping it's just days more rather than weeks. during this time, i need to keep the filter running 24/7, correct?
And, the water has been clear; I can see to the bottom. the only visible green was adhering to the sides of the pool surface in a few small patches; and, that's no longer there. however, i continue to vacuum and brush several times a day. If i can figure out how to post a pic i will upload it here. thanks again!

 

[AftonJeeper]

Yes keep the pump/filter going 24/7. You might have algae hiding on the weir door of the skimmer or in a light niche. Look for places it could be hiding.

 

[sas90]

here are some

 

[mknauss]

Not long.

Look at the hiding places mentioned before.

Take care

 

[sas90]

ok - thanks!

 

[harleysilo]

Looks great! You are doing a great job keep it up!