Danville's Pool

[CarlD]

Oh boy... I'll bet his CYA is 1346.3 ppm!

[danville]

Thanks for your help everyone.

Here are my stats:
- Pool is in ground in California in a very hot, dry climate. It is plastered (if that is the right term for the pool floor, if not please correct me).
- Very little visible algae growing. 3-4 dime size patches of reddish algae on the stairs.
- Water looks clear to me although the pool servicer told me it looked slightly cloudy to him. I am new to owning a pool so maybe I can't see the cloudiness yet.
- CYA level: 150
- Chlorine: 0
- ph: 7.8
- TA: 160

A pool servicer told me I had to drain it and power wash the walls or it would be green within 2 weeks. I had him add a bunch of liquid chlorine and 2 weeks have gone by and it looks fine. Chlorine is at 0 again of course but his prediction that algae would grow rampant hasn't come true. So I am hoping I can squeak by this summer by adding a lot of chlorine frequently. Can you advise if it is still safe to swim in this given the very high CYA level (I appreciate Pool Doc's response but just want to double check now that I have posted the CYA level)?

Any other advice would be much appreciated.

Thanks very, very much.

[Watermom]

How did you get a cya reading of 150? I don't think any of the testers differentiate anything higher than 100.

So, apparently it is at least 100? That is WAY HiGH for cya. If you can't afford to do a partial drain and refill, then you will have to run high chlorine levels to compensate for the high cya. Take a look at this chart:

Stabilizer . . . . . . Min. FC . . . . Max FC . . . 'Shock' FC
=> 0 ppm . . . . . . . 1 ppm . . . . . 3 ppm . . . . 10 ppm
=> 10 - 20 ppm . . . . 2 ppm . . . . . 5 ppm . . . . 12 ppm
=> 30 - 50 ppm . . . . 3 ppm . . . . . 6 ppm . . . . 15 ppm
=> 60 - 90 ppm . . . . 5 ppm . . . . . 10 ppm . . .. 20 ppm
=> 100 - 200 ppm . . . 8 ppm . . . . . 15 ppm . . .. 25 ppm

This means that you will have to be diligent about keeping your chlorine level between 8-15 ALL the time or you will risk an algae bloom. Also, in the event that you do need to shock the pool, you will have to take it up to 25ppm. Actually, since the chlorine level has dropped to 0, there is a good chance that you have something brewing in your water and just can't see it yet. I would suggest going ahead and shocking this pool to 25. If you test in the evening and don't lose more than 1ppm of cl from sundown to sunup, then you are ok. But, if you do lose more than that, shock it up again.

If you decide not to do a partial drain and refill, you will have to have a good test kit to be able to test the high cl levels you'll have to keep in your pool.

[danville]

Yes our testing kit only goes to 100 CYA, but the pool tech we consulted had a kit that went higher and he was the one he told us it was 150.

Sounds like we should go ahead and drain the pool. The pool is an inground concrete pool about 10 years old in a warm California climate. We are novices as this is our first pool - any advice on how to best drain the pool? Anything we need to look out for to avoid damaging the pool? Should we use a pressure washer once the pool is drained?

Thanks for all your help.

[Watermom]

In a dry area, you most likely have a low water table which is good when it comes to draining pools. You shouldn't have any problems. I assume you have a bottom drain. Not sure about the pressure washer. I'm gonna let someone else answer that part of your question for you. Probably ok as long as not the highest pressure but see who else chimes in on that.

[polyvue]

Yes our testing kit only goes to 100 CYA, but the pool tech we consulted had a kit that went higher and he was the one he told us it was 150.

Sounds like we should go ahead and drain the pool. The pool is an inground concrete pool about 10 years old in a warm California climate. We are novices as this is our first pool - any advice on how to best drain the pool? Anything we need to look out for to avoid damaging the pool? Should we use a pressure washer once the pool is drained?

Unless, as Watermom said, you have a high water table, or it's rained heavily in recent weeks (it's certainly dry enough to drain a pool where I am, in Sacramento) it shouldn't be a problem.

You don't have to have a bottom drain if you're willing to rent or buy a light weight sump* pump (less than $90 at Home Depot, Lowes, etc.) If you have a pool equipment controller or pump timer, be sure these are in service mode or turned off. I wouldn't recommend leaving the pool in a drained state for more than a few days, just start filling right away -- multiple hoses will speed the process.

Not sure what power-washing would do for your pool -- other than risk plaster damage. If you have a mild algae condition, spend a few minutes on the algae stains with bleach and a bristle brush, then fill it up. Maintaining a higher-than-usual chlorine level and brushing once a day will eventually work to remove staining deposited by algae growth.

EDIT * I meant a submersible pump, not necessarily a sump pump. END-EDIT

[CarlD]

My problem with used sump pumps is where they were used! Talk about a chlorine demand! (thankfully, chlorine will ensure a sanitary aftermath.)

[danville]

We do have a bottom drain. May be a silly question but how do I drain the pool from that (as you can see I am a newbie)? Would I just connect a hose to the pump somewhere? Given that I don't really know what I am doing and this will be a little trial and error, is there any equipment I could likely mess up by playing around to figure this out?

Many thanks.