Help with pool

[tim665214]

This morning I tested my water about 30 minutes after the sun came up, and FC was at 25.5. I just tested again and my FC is reading 24.5. (After being in the sun for about 4 hours) So I think it is safe to say that chlorine levels are holding. Also, I am not seeing any algea on the bottom of the pool. I am going to start letting my chorine level come down to around 9 or 10. (I measured my CYA level twice, and it seems to be between 80 and 90.)

Does everything sound ok? If I happen to see a little bit of algea this evening, could it be what I was unable to vacuum yesterday that just settled down, or would it mean that I definitely still have a problem? I don't think my CC is at 0, but it is definitely less than .5

Also, when would it be ok to test my ph again? How low do I need to let my FC level drop before I can get a good reading?

I think I am on the right path, but any help or assistance would be greatly appreciated.

Thanks

Tim

[tim665214]

This evening when I checked my pool, I didn't see even a trace of algea for the first time in a while.

I held my pool at 25 ppm all day yesterday, and this morning I tested, and saw that it held all night. Also my CC is almost 0.

I noticed my FC level tonight was 16.5. Which means I dropped about 8 ppm today. Does this seem right? My CYA level is between 80-90 and I live in N.E. Texas where the temperature today was 105. (No swimmers today) Hopefully I will not lose 8 ppm every day.

Is chlorine loss linear depending on level? For example, all other things equal, if I start out at 24 and lose down to 16 in a day, would I lose down to 2 if I started at 10 that day?

If anybody can offer any advice/tips I would really appreciate it. This has been a long battle that I believe I am at the end of, so I don't want to do anything that would cause me to have to start over.

Thanks

Tim

[PoolDoc]

Hi Tim;

It's hard to judge whether your pool's chlorine loss is above normal or not, till you have been able to hold things stable for a while. In general, chlorine loss seems dependent on the CYA/CL ratio + pH more than on absolute chlorine level. BUT, chlorine demand can be fast or slow, depending on what the source of the demand is. For example some components of urine are oxidized slowly, and will continue to exert chlorine demand for quite some time after the 'incident'.

In fighting algae, one very important factor to keep in mind is that it's not over till AFTER you think it's over. In other words, keep brushing and keep the chlorine high for several days AFTER there's no detectible algae. Also getting in the pool and feeling for 'slimy' spots can be a very effective 'early warning' method in vinyl pools.

I'll get back to you later today, with some more info.

[tim665214]

Thanks for the advice. This morning my pool still looks good. No visible algae. I tested this morning and my FC is 15. With my CYA level between 80 - 90, this is too low for a shock level, and too high for a normal daily level. Should I take the chlorine back up to shock level for another day or two? Currently my pool is holding levels overnight, and I would guess CC is around .2. (With a 10 ml sample I put the drops in for a CC test and the sample barely turns pink. And then I add just 1 drop of the next re-agent, and it immediately clears up. So it is definitely less than .5)

Since I live in a very hot area of the country, I am thinking I want my CYA levels around 75. But until my levels drop to that from splash-out and backwashing, I plan on keeping my daily chlorine level at 9. Does that sound right? (Current CYA 80 - 90)

[PoolDoc]

Your plan sounds OK (FC=9; CYA=90), but yes, I'd recommend keeping the chlorine high for several days after all trace of algae is gone.

Also, I'm working on a project that will allow all subscribers to log their pool readings via a smart phone or net device (it's a page, not an app), AND have their dosing info auto calculated for THEIR pool. I'm just starting on what you might call 'beta' testing today. If you are interested, email me at poolforum@gmail.com You don't have to have a smart device to participate, however.

[Watermom]

You don't have to have a smart device to participate, however.

But whut i want to no iz, duz yoo gots to bee smart??

(Looks like you and I were posting at the same time again.)

[PoolDoc]

But whut i want to no iz, duz yoo gots to bee smart??

Are we speaking W Virginia hillbilly, now?

[Watermom]

Since you reported such a big loss during the day on one of your recent posts, keep your chlorine at shock level for a little while longer. (With a CYA of 80 or 90, you wouldn't expect to see such a large drop in FC in one day)

Once you are in maintenance mode instead of shocking mode, you'll want to keep your chlorine between 5-10 all the time.

As far as the pH test, with a K-2006 kit, I think as long as the FC is below 15, your pH reading should be accurate. (With other kits, the FC needs to be below 5.)