Help with Levels

[jtwilllearn]

Hi all,

Thanks for all the wealth of information on the site. I’ve been on the site for the past year but finally joined as a member and now need some support on my own levels. I accidentally had the SWG cell off when I went out of town and returned to a bad alfae build up. Needed to SLAM the pool but CYA levels were just outside the upper limits. Algae is all gone, but my numbers are as follows:
Note: I test with a TF-Pro.

FC: 41.5
CC: 0
pH: 7.8
TA: 60
CH: 225
CYA: 110
Salt: 3800
CSI: -.71

Do I need to consider draining some water to solve for the high CYA, FC, and Salt? The high temps are still mid to upper 80s, so should I just wait until temps increase and FC drops? I’d still have increased CYA at that point at address.

Thanks,

 

[YippeeSkippy]

JT, welcome to posting
Do you know *how* your CYA got so high? I do think its in your best interest to drain your pool down to about 70ppm. Use
PoolMath to help you determine how much water that will be?

Your FC will drop over time....but the water exchange will speed that up.

I don't see a signature line detailing your pool, size, equipment, etc....... (please make it happen under Settings) and without knowing your SWG I don't know what the device wants for a salt level. Check your manual and then the water exchange can help that also. But its always good to know how much it needs to run.

Maddie

 

[YippeeSkippy]

Just saw your info about your pool.. Darn but your SWG is a T-3 is just a bit smaller than we like folks to have. We always recommend a cell at least 2x the pool's volume and yours comes in at 15k.

Do you have to run your pump a lot to keep things clear and sparkly?? Has algae been a problem before since your CYA is so high??

Next time you replace the cell, move up to a T-5, 'k?

 

[jtwilllearn]

Hi Maddie. I’ve updated the signature. Thanks!
SWG appears it likes 3500 as an upper limit.

Tough to say how CYA increased that high.
As too often is the case with new members here, I was relying on pool store assistance for too long and had low CYA at which point stabilizer was added. I haven’t stepped in their stores for almost a year now. I’m thinking it may have also increased from the shock that was added (I’m trying to get rid of the last bit of Dichor that I have left).
I thought the amount of water added this winter (rain and winter storm in TX) would have diluted the CYA down.

Also planning to also get CH a bit higher as I have some new pitting on stonework. Assuming I drain, I’ll wait to adjust any level until that’s complete.

 

[YippeeSkippy]

A drain of ~40% should get your CYA level down to 70

 

[jtwilllearn]

I usually run my pump about 9-10 hrs during the open season and haven’t had significant algae issues before with that schedule.

Makes sense on the cell size. What is a recommended timeline to replace cells? This one is 2-3 years old.

 

[YippeeSkippy]

Not until it dies My first cell (2.5x over the pool) lasted 9 years. You've got a few left.

But anytime your testing shows your FC is low, use liquid chlorine to get it in immediately. You don't want algae! I've never once had algae in 10 years of pool ownership.

Keep up on testing and get that CYA down. It will make things a lot easier.

Maddie

 

[jtwilllearn]

Thanks. I plan to rent a subpump this week and get it drained refilled.
My fiberglass pool doesn’t haven’t a main drain so I would be limited to draining only to the level of the skimmer if I was forced to drain through via the filter.

I’ll send the rest of the Dichor to a neighbor and begin using liquid chlorine to supplement the SWG.

Any other recommendations? Appreciate the help! I assume the levels in PoolMath are what I want to shoot for.

 

[jimbethesda]

I thought the amount of water added this winter (rain and winter storm in TX) would have diluted the CYA down.

Remember, it’s the amount of water you REMOVE from your pool that will reduce the CYA. If you didn‘t get enough rain to have to drain some, it wouldn’t have any effect.

 

[YippeeSkippy]

<slaps head> FIBERGLASS POOL!! Eegads, do not drain more than 20% of the pool at a time and refill, mix well and drain again and refill. Then test the CYA level. You may need to do it a 3rd time.

Fiberglass pools are like boats. If the boat is too empty or light it is going to pop up. We don't want that, hence the slow repeated exchanges of water.

Yes, you use more water in the end but better safe than sorry. Ok??

Maddie

 

[jtwilllearn]

Great point Jim.
Maddie - thanks for that. I have a 3” opening after the filter so I think I’ll drain via the filter a couple of times next week until I get CYA down.

 

[Prickly]

You can safely drain a fiberglass pool using the tarp method if you don't want to drain in multiple stages. I did a full water replacement with the method and it went smoothly. You just need a tarp quite a bit larger than the pool and you pump out from under the tarp while filling on top of the tarp. There is no tension on the tarp as it just floats on the water.