My first SLAM and how I got here

May 31, 2016
24
San Jose, CA
Pool Size
25000
Surface
Plaster
Chlorine
Liquid Chlorine
Hi folks. I'd like some feedback on the SLAM that I'm currently going through. I'll give you a bit of background first.

My family moved into a new house in February 2016 and inherited a pool which we never planned on having. I knew nothing about maintaining a pool. The previous owner showed me what to do (tough to absorb in 30 minutes) and with everything being so busy with moving into a new house, I thoroughly ignored the pool. Supposedly the equipment was on timer, and supposedly the UV light was sanitizing the pool (I now know better), but I didn't even check on it until May. When we peeked under the solar cover, it was a green mess.

We hired a pool maintenance company and they did clean things up so that all the visible algae was gone and the pool looked great. I then found this forum and I decided that I could maintain the pool myself and do it better. I ordered a Taylor K-2006 test kit, started stocking up on supplies and got ready. Supplies being only CYA, muriatic acid (I used an inherited test kit and knew the pH was a little high) and bleach. I did inherit a bunch of other stuff (algaecide, bags of shock treatment and a bucket of trichlor tablets), but I plan on giving them away or throwing them out.

I'll give you a subset of my measurements starting when I got the Taylor kit.

2016-06-13

FC 0.8
CC 1.0
pH 7.8
TA 100
CH 500
CYA <30

When measuring the CYA, the fluid was quite clear, so it was probably much closer to 0 than 30. I have no idea what the pool guys had used in the pool, so I don't know whether to be surprised or not. But the measurement was what it was.

I knew the first thing to do was to get chlorine in the pool, but every addition immediately yielded a boost of the CC and nary in increase in FC. Clearly, I had work to do. I knew I would have to SLAM, but first I wanted to get the CYA up. Unlike the chlorine and muriatic acid, that takes a bit of time, so I got started with that. I decided to use the sock in the skimmer method (which I felt comfortable doing since I ran the pump continuously) and put in 3 lbs. of CYA granules. Using the pool math calculator, that seemed safe because whether I was at 0 or close to 30 (which I did not feel I was based on the clarity of the test fluid), I would still end up well below the upper range of 50.

After doing that, I tested again and was still below 30, but closer (as I could tell from the cloudier fluid). So I put in another pound of CYA and after that, I was right around 30. (Dot was barely barely visible when my test container was full to the 30 line.)

I was eager get started, but unfortunately this weekend was not a good one because I would be away so much. But life is what it is, and I really wanted to get started on the SLAM.

Yesterday (Thursday), I used muriatic acid and adjusted the pH from 7.8 to 7.1. Maybe too low, but I thought I had read that a lower pH during the SLAM was desirable. In any case, the previous owner told me that the local water was slightly alkaline and that he never had to raise the pH, only lower it. So after I'm done, I'll either let it climb naturally, or I can raise it myself. In any case, I figure that was acceptable for SLAMing.

I've been doing many measurements during the SLAM, but I'm not bothering with the TA, CH or CYA as those shouldn't change much (and TA and CH aren't relevant until post-SLAM). So here we go:

2016-06-17 17:45
FC 0.4
CC 2.0
pH 7.1
CYA 30
Added 420 oz. 8.5% bleach to attempt to raise FC to 12.

2016-06-17 19:00
FC 3.0
CC 2.5
Added 363 oz. 8.5% bleach to attempt to raise FC to 12.

2016-06-17 20:30
FC 1.5
CC 7.0
Added 420 oz. 8.5% bleach to attempt to raise FC to 12.

2016-06-17 22:15
FC 1.0
CC 1.0
Added 400 oz. 8.5% bleach to attempt to raise FC to 12.

2016-06-17 23:00
FC 9.0
CC 1.5

Finally! And to think I almost posted this w/o doing that last measurement.

I am going to stop for tonight and continue tomorrow morning.

Btw, I will note that throughout all of this, the pool is visibly looking great. But apparently something was going on there which was keeping my pool from holding FC, so hopefully that will be rectified after this SLAM. I would never have known that if I had not taken my own measurements. And if I had not educated myself here in this forum, I mightl blindly have believed that 1.5 ppm FC is sufficient without understanding that it's dependent on CYA. (Nor would I even have known that I wanted to increase the CYA level to preserve my chlorine!)

Before that last measurement, I was getting kind of discouraged (I had to make a trip to get more bleach at 9:30 p.m.!), but I would have kept at it. While it seems crazy that adding so much bleach could not increase the FC, obviously something was going on, and I guess the boost in CC was evidence of that.

I have many other questions that I will ask later. You know what has kept me from posting earlier? The fact that I didn't have my sig filled in. Heh. But thank you, TFP. You guys are great!

Mason
 
Welcome to TFP, way to keep at it :)

Your now keeping FC and its holding, keep up the great work, test only FC and CC now until your SLAM is done, try testing from 3 to 8 times a day and add to keep FC at 12 as much as humanly possible

brush, brush, brush that pool after every add...

You will get there :) I see your sig..
 
Thanks, cowboycasey.

Here are some updated numbers from today:

2016-06-18 09:30
FC 0.5
CC 1.0
pH < 7.0 (is this normal to go down? It was close to 7.0)
Added 444 oz. 8.5% bleach to attempt to raise FC to 12.

2016-06-18 10:15
FC 14.5
CC 1.5
Did not add any bleach.

2016-06-18 13:30
FC 4.5
CC 0.5
Added 280 oz. 8.5% bleach to attempt to raise FC to 12.
 
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