SLAM question

[aralph]

Good afternoon. Long time lurker and this is my first post. First I would like to thank everyone for all of the valuable information on this site. I have been researching for awhile and have decided to put the SLAM to the test. Bought a home last year with a pool (previous home had a SWG pool) and was new to chlorine sanitization. Last summer I did very little to the pool as the water remained clear. The only thing I did was add pucks to the chlorinator and soda ash from time to time. This Spring it caught up with me and the pool got extremely cloudy and then started getting a greenish tint so I thought it was time to take action. TC was zero and CC was 2. I started SLAM this past weekend (bought a FAS-DPD tester first but ran out of solution very quickly! Have a big bottle on the way). Turned the chlorinator off and ran the bleach up to 20 ppm once in a.m. and once in p.m. for 3 days. After a couple of days I noticed IMMEDIATE water clarity results. After the third day the water was as clear as bathtub water. However, I'm still losing FC at an alarming rate (10 - 15 ppm overnight), and CC keeps creeping up from 0 to 1 or 2ppm. I have dumped an enormous amount of bleach into the pool and just wondering how much further I need to go before I see results with the FC stabilizing? I'm going broke buying bleach and am trying to keep it at 20ppm. Should I be adding it more frequently than twice a day? I do have to go to work so can't add as frequently as I'd like. The pool does get a tremendous amount of all-day sunlight. Here are my other levels:

TA: 80
CYA: 50
ph: 7.5

 

[Texas Splash]

Hello aralph and welcome! If you are truly following the TFP SLAM as instructed, then yes ... you will find yourself using a good amount of bleach - especially in the beginning of SLAM. As much as needed throughout the day to stay at the SLAM FC required. The free chlorine is battling the organics in your water, so the initial phase takes constant attention and bleach to stay on top. A SLAM can take a few days, or up to a week or two depending upon the condition of the water and the pool owner's consistency.

Make sure you keep at your FC SLAM until:
1. Water is clear
2. You do not lose any more than 1ppm of FC overnight (that's the OCLT)
3. CC (Combined Chlorine) is <.5

If you have any questions, see the links below in my signature for additional guidance.

 

[Mike1162]

I'm assuming you are brushing the pool & have no visible signs of algae. Have you also checked under the steps & inside the light housing? I'm also in the process of a slam & its close but not quite there. Today while swimming with a mask, I noticed a little algae inside the bottom drain. I'm about to go take care of that. I'll have the filter off for that, people have drowned & been disemboweled by bottom drains with missing or broken covers. Also give all the trim pieces around vacuum ports, skimmers (around the inside & outside), stairs & return ports a good brushing. Basically wherever there is a nook & cranny you probably have some algae remaining. If all of the previous items have been taken care of then it's time to give the filter the best cleaning of its life.

 

[aralph]

Yes. Brushing and then some. Took your advice and checked all the hard to reach areas this week but no hidden algae found. I didn't have time to do major bleach add this week and pool went from an oasis to cloudy almost overnight. Starting SLAM again this weekend however I just added 35 gallons of bleach tonight and only got my FC up to around 15ppm. It was getting eaten up almost as fast as I added it. Am wondering if I have an ammonia problem and the 20ppm FC raise just isn't cutting it? At this rate I need to go rob a chlorine plant. I'm just that desperate.

 

[Mike1162]

http://www.troublefreepool.com/threads/73192-Deep-Cleaning-a-Sand-Filter

 

[tim5055]

Chlorine consumption is a chemistry issue, not a filtration issue. From reading your two posts I get the feeling you are really not conducting a SLAM, but more of shocking the pool a few times.

With your CYA of 50, your shock level is 20. The idea is to,get to 20 and keep it there. You maynhvae to add chlorine multiple times a day. The more times you test and adjust the better.

You do not have an ammonia issue. You may have when you started, but you don't now. You would never be able to,measure FC 15 with ammonia in the water and the chlorine is consumed almost immediately as it oxidises the ammonia.

Slow and steady is the way to do it. It is a marathon, not a sprint. If you are off this weekend test and adjust the FC back to 20 every hour.

 

[Pogueld]

Be sure you are KEEPING the Chlorine level up to SLAM level as much as possible and your SLAM will proceed along quickly. When you are home, check the FC and add bleach every hour. When you notice it isn't dropping as quickly, you can go to every 2 hours. On times when you aren't at home, overshoot the FC level (up to mustard shock) before you leave the house and then when you come back home check as and add bleach often as possible.