High CYA in 2 week old hot tub?

Kpax755

Member
May 11, 2020
21
Columbus, OH
Hello I have a 2 week old 500 gallon Hydropool with Ozone. I have been adding 2oz of granulated Dichlor daily as we have a large family of 7. Today I tested the CYA as very high around 200-300.
Am I doing something wrong that this happened so soon? I am aware of the regular bleach method, or is there method I should use?
 

Donldson

TFP Expert
LifeTime Supporter
Jun 12, 2009
4,390
NW Ohio
28 ounces of dichlor in a 500 gallon tub would raise the CYA level to 211. So that seems to be right on. Though I am curious what test you used to get that number...

Only option now is to drain and refill. You definitely don't want to get in a tub with that high CYA level.
 

tim5055

Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
10,890
Franklin, NC
2oz of Dichlor will add 15 CYA , so in 2 weeks your CYA would be 210ish

Drain, use the Dichlor for two days then start using liquid bleach.

 

tim5055

Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
10,890
Franklin, NC
Thanks. I am getting .5 FC reading due to Ozone I assume?
17 would be immediately upon addition. Depending on the organics in the water and yes the ozone, it will go down. Ozone is helpful in removing CC in a coverd pool and covered tub.

Yours is a new tub I assume , so the ozone is probably working - but many times we find that folks who have ozone tubs it isn't. My previous tub had it and I discovered the nipple on the ozone generator had broken off so the tube wasn't even connected. Ozone is one of those things that is many times better on paper than in real life.
 
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Kpax755

Member
May 11, 2020
21
Columbus, OH
So it seems like I've been using WAY too much Dichlor in my tub. After I drain and refill, I can either go with the Dichlor/bleach method, or would it be ok to use Dichlor ONLY but maximum dose of around .25 oz per day? By using pool math that should be sufficient for my size hot tub? 430 gallons. Last night I added .25 oz of Dichlor and it took my FC up to 8. With my ozonator that should be down to around .5 after 24 hours. Is that correct? My local spa dealer seems totally clueless on why I am checking my CYA levels and tells me to just keep adding Dichlor...

If I use bleach, is this liquid chlorine ok to use from Walmart? Looks like I would only use about an ounce according to PoolMath?


TIA!
 

tim5055

Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
10,890
Franklin, NC
After I drain and refill, I can either go with the Dichlor/bleach method, or would it be ok to use Dichlor ONLY but maximum dose of around .25 oz per day?

If I use bleach, is this liquid chlorine ok to use from Walmart? Looks like I would only use about an ounce according to PoolMath?
I find it easier to just keep a bottle of liquid around. I have a small table under coverf on my patio that I keep my test kit and a bottle of bleach on. When I get out of the tub (which I just did) I add my liquid.


My local spa dealer seems totally clueless on why I am checking my CYA levels and tells me to just keep adding Dichlor...
Which is why we say don't trust chemical testign or advice from most "pool professionals"
 

Kpax755

Member
May 11, 2020
21
Columbus, OH

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
17,933
Northern NJ
Hey all, is bleach ok to use? I can't read the label very well in the pic? Trying to find something that can be delivered and not crazy expensive.

No, label says it has Cloromax Technology which are polymers you don’t want in your pool.