Updated numbers with TF100

[dravenone]

Last week I posted my first numbers with the TF100. After more research on the boards I realized I was not performing the CH test (and possibly others) properly, I also had dropper issues and needed to wipe the tips fixing the problem. After doing so, I am re-posting my first test numbers and today's numbers with proper swirling and drop size.

Old
FC 9.5
CC 0.5
PH 7.2
TA 130
CH 1200
CYA 100+l didn't reach first line on test

Today
FC 5
CC 0.5
PH 7.2
TA 100
CH 550
CYA 100+ Still don't reach first line on test


Please keep in mind I will be switching to a SWG in the coming weeks and the water is currently clear. It looks like I still need to do a partial drain to get my CYA down which I guess will bring down my CH some. Just looking for a ball park recommendation of how much to drain based on new numbers. Thanks!!

 

[JasonLion]

Alright, CH at 550 is very high, but can be managed. The important thing with your new numbers is to get the CYA level down to 80 or so. To do that we need to know what the CYA level really is. The CYA test can read numbers much higher than 100 as 100.

Try mixing equal amounts of pool water and tap water together, do the CYA test with that, and multiply the result by two. That will lose a lot of precision, but it will give you an idea if your CYA level is closer to 100 or to 200.

 

[dravenone]

I performed the adjusted CYA test and my CYA is at 200! Plugged my numbers into the pool calc and it returned a 60% water exchange. Does that sound right? Now that I think about it, how do I determine I have drained enough? My pool is 3' shallow and 8' deep, will eyeballing it get me close enough?

 

[duraleigh]

will eyeballing it get me close enough?

Sure. You may not get enough the first time and have to drain a little more but you are simply diluting the water in your pool to get CYA to a manageable level.

Do not drain so much from your pool you risk it "popping" from the ground. Generally, if the water table is low where you live, that problem will never come up. That said, if you live in the swamp with standing water in the back yard......don't drain the pool!

A partial drain will help with both CYA and CH management.

 

[JasonLion]

Your CYA level could still be higher than 200, again because the test will read numbers larger than 100 as 100, which you then multiplied by two. Hopefully your CYA level isn't too high.

You don't have to get the water replacement amount exact. If you are off you can always replace some more water later. It is slightly more efficient to get it done in one pass, but the difference isn't all that large.

Note that before draining a large amount of water, you want to be confident that you don't have a high water table. If it has been raining a lot recently, or the area the pool is in tends to be swampy or wet all the time you don't want to replace too much water at one time.

 

[Guest]

If your CYA is extremely high (as yours is) it can take a few drain an refill cycles to get it in line. The good news is that once you do there is no need to ever have to do that again if you follow the advice on this site!