Is my CYA level too high?

[Laurab]

We've been using the local pool store and following their directions for pool care but doing a lot of reading on our own as well, and ended up joining here today. Had some metal staining and per their directions dropped the chlorine level down to treat last week. In the mean time the old pump is getting louder and louder, so after the metal treatment we decided the neighbors would prob rather not hear the pump so we turned it off-last Friday. New pump this past Monday and now trying to get rid of the green sediment on the bottom of the pool. Same day took a sample of water in and these were the readings before starting algae treatment:
TC 2.0
FC 2.0
CC 0.0
ph 7.5
TA 110
CH 310
CYA 100
These were the instructions given:
shock pool with 1.4 gal of liquid chlorine wait 24 hours then add 22 ounces of all in one algaecide according to directions. Brush walls and floor of pool and let filter system run for 24 hours. Ok, we were at this point this morning, when I brushed the pool there was lots of yellow green billowing up, I vacuumed instead then we cleaned the filter, it was bad, and added the next recommended shock treatment, another 1.4 gal. although directions said to wait 48 hours, we waited less than 24. Maybe a mistake? Trying to clear it up for hubby's chill day! It does look like it's trying to get better, maybe just from cleaning the filter, but I just went out there to check and when I brushed there was def more algae not as much as this morning, but at this rate will prob be bad tomorrow morning. From what I've been reading it could be that my CYA level is making the chlorine ineffective, the pool store never says anything about that. Also is there a relationship between high CYA levels and metal staining?
Looking forward to some help! Thanks!!

 

[tim5055]

Welcome to TFP!!

100 is the limit of the CYA test, so at this level we are unsure if it is 100 or some number above 100.

If you have read around here much you have probably seen that not much credence is given to pool store testing. While you would think that a "professional" would be the best, unfortunately in most cases it is quite the opposite. Between employees who blindly trust the word of chemical sales representatives and high school kids working in the pool store for the summer you end up with poor results from their testing. In my case two different pool stores told me my CYA was "fine", around 70 or 80. When I tested myself I found it over 200.

To follow the pool care methods taught here you need to arm yourself with the knowledge and tools necessary to care for your pool.

The knowledge is condensed in the Pool School link at the top of every page. It is a great community here, but we do ask that you read and try to understand the information being taught. Questions are always welcome and folks will try to direct you and teach you the methods.

The tools are not limited to the brushes, vacuum hoses and other stuff you use around the pool, but include the most important item - one of the recommended test kits. You can buy a kit at a pool store, but again the pool store kits generally won't cut it. To effectively practice the TFPC methods, the FAS/DPD chlorine test is essential. All these kits contain that test while very few other kits do. Think of it this way, do you see a doctor blindly prescribing drugs without seeing the patient or having tests run?

I would recommend you order a TF100 and at least include the XL option. That will give you what you need while you are clearing the pool, and probably enough reagents for a couple of years normal use.

The only other real option for a test kit is a Taylor K-2006. Be careful comparing prices because the K-2006 comes in sizes, designated by a letter. The basic K-2006 has .75oz bottles. Yo need to get the K-2006-C to get the larger bottles that you want. Even then it is a little short on the reagent & powder for the FAS/DPD test.

I also have the SpeedStir and Sample Sizer. They speed testing and accuracy.

 

[kimkats]

Another Florida person! Sweet!

You really need to get your own test kit.

Yeah I know the pool store will test it for "free" but is really free? When you have to spend $$ every time you go in.............it is not so free.

If you get your own test kit you will only have to go to Walmart and Lowes! Pretty neat huh? Bleach is your main thing for having a clear pool.

Hugs and welcome!

Let us know when you get your test kit!

Kim

 

[Texas Splash]

Uh oh. Another one from :sun: FL.. We better up the recruiting for TX again. Welcome. Lots of advise already, so I'll simply say welcome. Make sure to click on the links you see in our signatures. Besides the right test kit (priority #1), those instructions will get you through 9 out of 10 problems. Have a great day.

 

[Laurab]

Thank you so much all...yes, I have been reading about the test kits, so I will be looking for one asap!! This is so frustrating...it is def pool time here in :sunny: Florida!! So I guess I'll have to get the test kit before I can proceed?!

Soooo, I'll be back!

 

[jonsimp911]

You definitely need to order a FAS-DPD test kit from tftestkits.net. In the meantime, to answer your questions.

If your CYA is truly 100 (it could actually be much higher), then yes - your CYA is too high for a manually chlorinated pool (no saltwater chlorinator). That would put your shock level at 39 FC.

As far as your concern regarding not waiting 48 hours before adding the additional liquid chlorine - if the CYA is truly 100 or higher, you have nothing to worry about. With a pool that size, 1.4 gallons of 12.5% liquid chlorine would only raise your FC by 13ppm. Even if you would have dumped it all in at once (2.8 gallons), with 2ppm FC you would be at around 28ppm FC - less than your optimal shock level if 39ppm w/ CYA @ 100ppm.

Get a test kit, and get an accurate CYA reading. If it's over 50ppm, you'll need to do a partial drain and refill. You can perform a SLAM to get rid of the algae at that point.