New supporter, and 11 year old pool owner here. I have been reading feverishly for the past week or so trying to get a handle on TFP methodology and all the chemistry. I "thought" I had a good understanding of pool chemistry, but I've learned a ton in the last week or so.
My pool is an 11 yr old 22k gallon IG, pebble tech, with a 60sf DE filter and SWG. My salt level (according to my fairly new cell) is 3400 so that should be good. Right now, my SWG is awaiting me to repair the bad varistor on the board, so it's turned off. I'm currently floating 3"tabs and use liquid chlorine as needed to boost, etc. As soon as I'm done typing, I'm going to go pull the tab floater out of the pool since I have a possible overload of CYA. More on that in a minute.
Last week, I ordered and received my K-2006 kit and ran my first set of tests. Here are my results:
1st overnight chlorine loss test showed a loss of 0.5 FC.
OK, so I have a few Q's.
First, I have the older style CYA test kit. It's the larger size tube that you fill up halfway with pool water and halfway with reagent, lift the plunger up and down for a minute, then make the black dot disappear off the plunger. I tested my water with that kit and I got 60ppm. I then tested with the k2006 and got 100+. I'm not at home so I plan on doing the 50/50 test with pool and tap water when I get home to get a more accurate reading. My question is how in the world can I be getting such drastically different results with these two kits. The old kit uses the same methodology as the k2006, so I'm scratching my head here.
Second Q. I'm wondering about my CH level. I tested our tap water and it has a CH of 250. My pool water is original so I haven't changed it in 11 years. My pool water is sparkly clear right now, and I have eliminated the algae that I had a couple of weeks ago when my SWG quit working and I didn't pick up on it quick enough. Other than the typical faint white line on the tile at the water line, I'm not experiencing any heavy scaling. Well, the exception is where the water trickles over the 5' wide opening from the spa into the pool. I have real rock spillway, and I do get some heavy white scaling in a few places. Do I need to do a partial drain to get the CH down? My thinking is that if my CYA is over 100, then I'll maybe do a 50% drain to kill two birds with one stone.
I ran out of time here, so gotta go for now. I appreciate all the info I've been able to glean from you all thus far. I'm glad I was able to support the forum and hope many of you lurkers will do the same. Looking forward to all your help.