Saturation Index

OK, so the aeration works quite well. pH right now is about 7.6 so it is going in the good direction.

You guys are here to give a good advice as usual. I appreciate any suggestions and I'm constantly learning. I definitely will wait with checking the CYA before I add anything more.

Not sure if I should start a new thread but... I described my situation here already so maybe it will be easier and something is telling me it is related since I didn't notice anything like that earlier. So I noticed today two problems. I would say quite big. Please see pictures below.

One issue is with the metal light case. It was covered in some layer of dust copper like color. Because it is under water my guess is that the light casing is rusting. It took picture when I already touched it a bit in the top part cleaning it, so you can see the bottom part of it still covered and darker. It came off easily, however as you can see it is all over, and in the holes, etc.


The second problem is related to the water feature. As you can see some strange and super visible stain developed in one section. Very strange that only there. Not everywhere. This is right top part, about 1/5 of the whole waterfall structure.

I could be wrong however I did not brush my pool in last 3 days so I do believe everything happened in a day or two. In the last days where I went up with the chlorine from 2ppm to 6ppm and CYA from 30+ to 70. My pH before was somewhere between 7.8-7.2. It doesn't make any sense to me because if pH was high... ok, scaling, but then I was trying to take pH down all the time with acid and never ended up below 7.2. LSI was usually -0.1 - 0.1

There is one element which I'm not sure about - my Calcium. Checking I realized it is very important especially for the start up so I run to the store (Leslie's) and tested it. They have new fancy electronic test and the result was 130 so of course they sold me huge bucket of stuff to raise my CH. I uses only a bit of it and since I already received my Taylor2006 I tested it again with a result of 375! WOW, so again to the store and checking and it shows 160. Go back home and Taylor shows 375. I emailed Taylor and they said it is almost impossible that I would have an old reagents so I should trust my own test. According to Taylor in last two months my CH is quite stable around 375, and according to Leslie's few different stores (using the same electronic test) my result successively climbed from 160 to 260.
Anyway, I can see that with LSI it is not a big difference if my CH is around 200, however with CSI the 200CH goes close to -0.4

Thanks for any suggestions.

Can't speak to the staining issues. I wouldn't have guessed rust though, because I don't think rust would wipe off like that. Hopefully someone else here will recognize them.

Don't overthink the TFP process. We CONSTANTLY warn new folks here about pool store testing. It's so common. Yours is just another example.

The single best thing you can do for your pool, your pocket book and your peace of mind: stay out of the pool store. Stop testing there. Stop buying their recommended stuff. Trust your test results. Trust the TFP process and the advice you're getting here. That's all you gotta do for now. You're still stuck on LSI. Start there. Just stop considering it. CSI is what you want to use, so use it. There... done.

When I first found TFP, Marty was my guardian angel, my mentor. He took great care of me and my pool. He knows his stuff, especially about pools located in the southwest. His posts are very short and sweet, and don't always go into the kind of detail people like you and me need for the way our brains process learning. But he helps a huge number of people, every day, and has to keep moving. He was super patient with me, as I needed to challenge everything (which is why I recognize me in you). But eventually I got it: not to overthink it, and just to embrace it. Most of his posts are simple one line instructions. He's already done all the analyzing in the background, we don't have to redo it. Just follow the instructions and you'll be golden. The whys of it you can get on your own, as I did, by reading and rereading Pool School and then some of the advanced articles.

Or not.

Oh, can you clarify for others: in the second pic, what is the stain you're questioning? The thin white, or the brownish color? Some rocks are naturally two-toned like that. We don't know what your stone looked like before. Is it the rusty color that is new?

Ohhh, I’m sorry, I should be more precise. Yes, the white lines (I updated the picture). It's actually very difficult to remove. I tried a stiff bristles brush, no any noticable change. Tried a metal brush and the stain is still there.

OK, let's see if we can get someone from here to help you with that.

The light ring is exactly 2 months old, and of course quality could vary, this is the Pentair one. I hope there is a better explanation especially considering my index and pH.

@duraleigh You confirmed my suspicions. Not happy but thank you. Unfortunately I had an issue from beginning with the waterfall leaking trough every possible corner at the back and front. The WF bowl was never fully sealed and then it was covered in pebble tech. It didn’t seal it either. I was able to fix some leaks by using thoroseal on not visible part of the bowl and a bit in the front. Looks like it did only a partial job and the stain is coming out as you described it trough those leaks :-/

A lesson for everyone who is still using stores for testing water or stripes, and it is not convinced to the own measurements >>
Seing the issue with staining I decided to drive around the city with my water sample to make sure I do not have issue with low calcium and I can verify how much my CYA changed. So far I checked calcium by myself and Leslie pools. result of my adventure is pretty shocking. Small stores use strips or reagents and Leslie uses LaMotte electronic test.
CH 235 (Leslie) 400 - 600 (small stores) 370 (my test)
CYA 68 (Leslie) 100-120 (small stores) 70 (my expecting result)
As you see there is no help with any store test and it’s crazy bad. I have to trust my own test and that’s it.

Additionally I noticed that my TA plummeted from 80 to 60, according to Leslie and all other stores. I saw some post about other person rising the CYA and resulting in very low TA, so I guess this is why it happened.

UPDATE: Ohhh boy! Why I'm such an idiot? I wrote that above before I came home. When driving I was thinking... how it is actually possible that my TA is 60 when my pH is CRAZY STABLE now. I already learned what means pH bouncing because my TA was out of range so... I’m not going to test any water again at any store. I just came home and tested TA and it is strong 80 as it was.

I have to admit that I educated myself a lot in last weeks, however reading TFP gave me strong understanding of many aspects and there is a big logic behind. Some could just blindly take it, I definitely needed to explore it and understand but... all comes down to the same - just follow the advice you find here Thank you guys!

It's definitely time to make myself a drink and enjoy my crystal clear pool, from time to time checking if anyone has some extra clue about that strange dust on the light ring. Perfect time to start reading about solar heaters since it is my next project.

So now I'm completely converted to TFP numbers. In last days I was very rigorously trying to get all numbers in the perfect recommended spot to get CSI close to zero. Unfortunately something strange is happening.

For about 3-5 days my numbers we quite stable and I was only working on raising my pH. On Saturday my TA was still 80 but on Tuesday night it was already 110 :-(
The pH went up to 7.8-8.0. My FC lowered a bit to 3.8 (testing SWCG settings) so I brought it up to 5.2 with liquid and ran OCLT. It was only -0.4ppm

My question is what could raise my TA so badly (30ppm). It is hot so there is evaporation. Auto refill does replace water but city water TA is only 140 ppm.

Any suggestions?

No bueno. Is there any way to maintain TA close to recommendation in that situation?

At this point I add acid, bring TA down, start aerating because pH is low, it takes a few days, and... my TA is again high so adding acid.... This looks to me like never ending story and nothing balanced, just a big swings with a risky long periods of low pH. If I crank up acid dispenser maybe my TA would stay low but pH definitely is going to be very low all the time.

I use a water softener to filter out my city's high CH, so that it won't build up. I don't think that works for TA, though. Perhaps there is a filtering system that would. (RO, maybe?) That way, once you got your TA down, you wouldn't be adding any more through your fill water. Just spitballin'...

Though there could be something else going on if it's bouncing back so fast. Gotta leave that to the experts...

Eureka ! and... Huston, we have a problem!

So I just found this on the Taylor website


Booklet takes you to the table and one simply equation TA (correct) = TA - ( CYA * factor ) The factor is based on current pH and is around 0.33

So my TA reading when I raised CYA to 70 was actually 86 instead of 110 as I thought.
Now, with pH 7.7, TA 90, CYA 80 & CSI -0.05 - my real TA is 62.8 so CSI is -0.3

@Dirk or @mknauss should I use baking soda and raise it a bit? (I'll be away for a week 🏕)
Do you all use that correction with high CYA ?

You don't have to do that correction. TA is TA, including the CYA contribution. The TA as it is determines the bufferering capability of your water. Calculating CA by subtracting the CYA contribution is only important for the CSI calculation, but Pool Math does this for you internally. You enter TA as measured into PoolMath.

There is a bit of confusion in the industry (obviously including Taylor) to subtract the CYA contribution and still call it TA - that is wrong. That's why we call it Total Alkalinity as opposed to Carbonate Alkalinity.

Edit: if you subtract the CYA contribution from TA and put this number into PoolMath, then PoolMath will subtract the CYA contribution a second time for its CSI calculation.

Thank you. It make sense. I use the PoolMath CSI so the numbers are pretty good now.