Liquid CYA

Re: SLAM with zero CYA?

We do not recommend the liquid CYA simply because it is so expensive.

True, but I had the same situation - CYA 0 and wouldn't hold chlorine and had to do a SLAM. I'd rather pay a bit more and have it done right away than wait a week.

Leslie's had liquid CYA for $47/gallon in the store, but they price matched a $27/gallon on their own website. That's only about $8 more than the granules at Lowes, and it was instant. I used 3 gallons and took my pool from 0 to 50. yes it's more expensive but sometimes it's worth it for the sake of time. I started my SLAM on Tuesday night and we're swimming today, perfect chems - CYA 50 / pH 7.5 / FC 6 / CC 0.
 
Re: SLAM with zero CYA?

If you want some instant CYA in the water along with chlorine, then just buy some Dichlor since that adds both. For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm. Just make sure not to overdo it; switch to bleach or chlorinating liquid once the CYA is up to where you want it.

However, as Jason noted, if you are SLAMing to kill algae, then most of the chlorine will be attacking the algae so gets lost that way. The half that would get lost to sunlight over an hour may initially be less of a loss. If that's a concern, then the Dichlor would be a less expensive approach of adding both CYA and chlorine.

Let's look at some calculations where I'll use prices at PoolGeek.com for comparison and I'll use 15,700 gallons from the thread where this came up.

GLB Stabilizer $36.19 for 10 pounds is $3.62 per pound.
GLB Granular Chlorine $35.99 for 8 pounds is $4.50 per pound.
Natural Chemistry Instant Pool Water Conditioner $26.25 per gallon. 1 gallon per 10,000 gallons raises CYA by 32 ppm.
12.5% chlorinating liquid I'll assume at $3.50 per gallon

Let's assume we ultimately want to get to 50 ppm CYA in the pool. Here are the costs:

104.8 ounces (6.55 pounds) weight of GLB Stabilizer is $23.71
(15700/10000)*(50/32) = 2.45 gallons of Instant Pool Water Conditioner is $64.39
208 ounces (13 pounds) weight of Dichlor is $58.50, BUT this is also 55 ppm FC so subtract the chlorinating liquid 884 fluid ounces (6.91 gallons) at a cost of $24.17 for a net "CYA only" from Dichlor cost of $34.33

So you can see from the above that the least expensive approach is to use pure CYA, but that using Dichlor would be an alternative for faster CYA addition but is 45% more expensive but the liquid CYA approach is 2.7 times (172%) as expensive. As a compromise, one could just use a smaller amount of Dichlor for an initial 10-20 ppm CYA and then switch to chlorinating liquid while waiting for the pure CYA to dissolve to get you the rest of the way.

In practice, the pure CYA will start to dissolve right away so that within a few hours you will have at least a little CYA in the water that will start binding to chlorine and protecting it from degradation from sunlight, but if you don't want to wait you can use Dichlor as a less expensive choice than liquid CYA, at least for the initial CYA that is added.
 
Re: SLAM with zero CYA?

Leslie's had liquid CYA for $47/gallon in the store, but they price matched a $27/gallon on their own website. That's only about $8 more than the granules at Lowes, and it was instant. I used 3 gallons and took my pool from 0 to 50.
To add 50 ppm to 23,000 gallons you would need (23000/10000)*(50/32) = 3.59 gallons which at $27 per gallon (about the same price as poolgeek.com, by the way) this is $97. You say you used 3 gallons which would cost $81 so that would add 41.7 ppm CYA, not 50 ppm CYA. You say that the required amount of pure CYA from Lowes was $8 less so $73, but that is a TERRIBLE price for pure CYA unless some calculation was done incorrectly.

For 50 ppm, you would need 153.55 ounces (9.60 pounds) weight of pure CYA so using your Lowe's price $73/9.60 = $7.61 per pound is more than double the price of GLB stabilizer at poolgeek.com. Kem-Tek 4 pound stabilizer at Lowe's for $15.98 is $4.00 per pound. Getting two of these so 8 pounds for $32 would give you 41.7 ppm CYA so the same as the liquid CYA you used, but a LOT less (2.5x) expensive compared to $81. So I'm not sure where you got that 9.6 pounds of stabilizer would cost $73 at Lowe's. That's why it "seemed" to you to be a fairly comparable deal. It really wasn't because 1) the pure CYA stabilizer price you used for comparison was ridiculously expensive and 2) you didn't calculate the full 50 ppm CYA amount for the liquid CYA.

As I wrote in the post above this one, if you want to get some CYA into the water right away to not lose as much in sunlight during the start of a SLAM when there is no CYA in the water, then you can just use Dichlor initially for that purpose. Though still more expensive than pure CYA, it's a far better deal than using liquid CYA.
 
Got it and that's always a personal trade-off. I just wanted to clear up the misconception about the cost difference since it was really larger than first described. I also wanted to make sure the Dichlor alternative was known. There's nothing wrong with what you did and I've done similar things when I was in a hurry. For example, after a phosphate remover experiment clouded my pool, I used a clarifier so that it would clear more quickly rather than just wait for filtration.
 

Enjoying this content?

Support TFP with a donation.

Give Support
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.