Spa Water Care

[MSLOANE]

Sorry for the long post, but need some advice as I dial in my water care plan for my new spa.

I have had my spa for about a month now and love it! It is a Hot Spring/Hot Spot Relay ~350 Gallons using the Frog @ease in-line SmartChlor and mineral cartridges. I use the spa about 20-30 minutes every day. Honestly, the cartridges do work, but compared to just raw chemicals, they seem quite expensive long term - I don't mind using them if I have to, but I believe I can achieve the same result long term cheaper with just dichlor/bleach and want to run some stuff by the experts here and look into cost benefit.

Through trial and error and poolcalculator.com, I learned out how to balance my water with spa down / spa up products. My water targets are : 80-100TA, 7.5PH, 120CH, 1FC (though really I want to see it at 3FC even though Frog says 0.5-1.0FC is where it should run given the mineral cartridge).

The only real trouble I have is the ph drifting upward and the alkalinity drifting downward but I can reign them in with once a week additions. Water is clear and crisp for the most part, though i do get some burning in the eyes every now and then but nothing crazy.

Given that my chlorine levels are running lower and my smartchlor cartridge is running out, I want to start using dichlor or 6% bleach. Today I checked my water and noticed that ph had risen to 8.0, which I corrected with dry acid. Chlorine was also low at 0.5 and i wanted to get it to 3.0, so I added dichlor at 0.6 ounces. When i checked my water again, my ph was at 7.2, and my chlorine didn't really change all that much. I also just learned that dichlor has a large impact on ph, which caused me to overshoot my ph target by 0.3. I then did some reading and found out i could also use 6% bleach without affecting ph too much, which i did at 1.5 ounces - after running jets for a bit i tested again, and my fc was only at 1, even after all that dichlor and bleach, but my ph had risen to 7.5.

Since bleach is so basic, could it cause a rise in ph at levels needed for proper chlorination and I got bad intel?
Also, is bleach even safe to use in spas as a means for chlorination/shock?
If i wanted to stick with dichlor, what is the proper amount of shock for the spa (350gallon)? I thought it was 1 ounce but didn't have luck...
How will Cya acid build up over time affect chlorination of spa, even if i plan to drain it every 3-4 months?

Any other words of wisdom on the sanitization side? trying to keep it simple lol thanks in advance.

 

[Jimrahbe]

M,

Welcome to TFP.. A great place to learn all about pool and spa care..

I think not replacing the mineral cartridge is a great idea.. You will find no love here or mineral systems..

Just for reference, I run my FC at about 5 to 7 ppm with a corresponding CYA per this chart... FC/CYA Levels I converted my spa to saltwater, right after I bought it. Makes maintenance pretty easy.

We always suggest using Muriatic Acid (MA) over dry acid... A bottle of MA will last "forever" with a small spa.

You really do not need to buy things like Spa up and Down, who's main job is to make the spa store richer..

I only add a little Liquid Chlorine and a little MA from time to time.. The salt system produces the majority of the chlorine that I need.

Like you, I drain every three or four months when I can no longer keep my CC level below 1.5 ppm.

Before I dump the old water, I use Ahh-Some, which gets rid of the gunk... Then add water, CYA, Calcium, and salt, and just start all over..

I do open the cover to let the sunlight burn off the CC's about two or three times a week for an hour or so.

Let's see what our other members have to say..

Thanks,

Jim R.

 

[MSLOANE]

thanks... my gut is telling me there must be a better way even though the cartridges do make it easy. appreciate feedback.

 

[MikeDelta62]

I used the Frog system with my new Relay until they were consumed. The system is convenient but relatively expensive. I had difficulty trusting the low value sanitation level. I could only find the Chlorine cartridges online. The Bromine cartridges were readily available locally. The sole source carts/test strips was one reason I moved away from this system. I was never exactly sure when the cartridge would be empty although I could guess based on weight.

If my TA was between 80-120 the PH would also drift high - especially with aeration. I typically maintain a TA of 50-60. The PH will then settle 7.6-7.7. I add calcium chloride to reach CH value of 160 the day after water balance is complete. I add Borates (Gentle Spa) the day after calcium chloride addition.

Reference : How do I use Chlorine in my Spa.

 

[MSLOANE]

so much conflicting information everywhere I look LOL. I agree with you Mike. Specifically regarding alkalinity i thought i was good at 100 - but im hearing people talk about lower levels... If i wanted to shock my spa with dichlor, what would be the appropriate amount for 350-400 gallons? I know i think the bottle says 1 ounce but i dont feel that actually achieves the desired effect. My water is clear but the chlorination level at 0.5-1.0 ppm bothers me.

 

[MikeDelta62]

My experience has been pool stores and spa manufacturers will normally recommend a TA of 80-120 for both spas and pools. I don't think you will find those values recommended on TFP with respect to spas. I use bromine and don't worry much about CYA but I would suggest using Poolmath to determine amount needed - maybe 12ppm. I've seen recommendations to not use the spa until the FC level is below 10ppm. I won't use my spa if my bromine level is above 8ppm. It's difficult to suggest an exact amount for you because you should use an accurate test kit and determine your start point at that time. As a bromine user I have a Taylor K-2106 kit with a couple of additions but if you are using Chlorine the TFP kit is fine and all the tools in Poolmath work without conversion. On an initial fill I will use dichlor to shock to about 15ppm and partially offset the high initial PH and Gentle Spa additions then switch to bleach, usually 6%.

From "How to use Chlorine..."
Sanitation
On a fresh fill use Dichlor until you get to 20-30 ppm CYA. (10 ppm FC = 9 ppm CYA)
Then switch to plain bleach or liquid chlorine.
Never let FC drop to Zero for any length of time. Keep it between 3-6 ppm normally, min of 1 ppm, and shock to 12 ppm once a week.
Use MPS if needed before hot tub party's and/or once a week to help oxidation. Don't use more than needed, because it's acidic and may lower your TA/pH.
Dichlor, Bleach and MPS is all you need to keep your tub sanitized.
Use PoolMath to calculate exact amounts to add.

Note: Don't let the first sentence mislead you. You don't "use Dichlor until you get to 20-30 ppm CYA" all at once. This is done over time as needed to maintain the FC level. After you have used that amount switch to bleach.