I need help!! Algea keeps returning

[poolsidechic]

So I am not the best with pool chemicals, I just do not know what to do. My pool has turned green again. Below are my test levels. If someone could help me figure out what I need to do I would be really appreciative.

FC - 3
CC - .5
TC - 3.5
CH 729
TA - 0
CYA - 70
CL- 5
BR - 10
ph - >6.8

 

[Texas Splash]

Welcome to TFP! I'm sure we can help, but let's confirm a few things first:
1 - How are you testing? Which test kit specifically?
2 - How do you normally chlorinate the water? What product? Tabs, liquid, etc?
3 - Are you on a well?

Please update your signature with all of your pool and equipment info. It will help later. See mine as an example. We'll get you through this along with our Pool Care Basics page.

 

[poolsidechic]

Welcome to TFP! I'm sure we can help, but let's confirm a few things first:
1 - How are you testing? Which test kit specifically?
2 - How do you normally chlorinate the water? What product? Tabs, liquid, etc?
3 - Are you on a well?

Please update your signature with all of your pool and equipment info. It will help later. See mine as an example. We'll get you through this along with our Pool Care Basics page.

Hi!
Thank you so much for your reply. I am using the TF-100 test kit from tfp. Normally I add one bag of shock to the pool on Sundays and then we have an automatic chlorinator on our pump. I use the shock in powder form from sams club and also tabs in the chlorinator from Sams as well. (I think they are called Members Mark). We are on a well and we live in the country where they just sprayed the cotton with some pesticide.
My pool is 12,000 gallon vinyl siding (purchased from Wal Mart 3 years ago.)

 

[Texas Splash]

Since you are using chlorine tablets, I'm not surprised that your TA and pH appear to be extremely low. That's very bad for your pool liner and equipment. I suspect the use of the chlorine tabs are partly responsible since they are quite acidic. Tabs (and those bags of shock) also increase your CYA which is getting too high for a non-salt pool in your area. So what to do now:
1 - Stop using tabs and bags of shock powders. Instead, rely solely on liquid chlorine (or regular bleach) to increase your FC level. They have no such side effects.
2 - Increase the pH and TA right away. Be sure you are performing each test correctly, if in doubt ask. But if you confirm those TA/pH results being low, take action to increase the TA to about 60-70 ppm and getting the pH up to at least 7.2. Use the PoolMath APP's "Effects of Adding" to help you with the dosage amounts. I would recommend increasing in stages and re-testing about an hour later to monitor for progress so you don't go too high. See below for ideas on how to increase the TA and pH.

PH can be raised in three ways: borax, soda ash, and aeration. Borax is usually the best choice. Borax raises the PH and also raises the TA level just a little. If your TA level is low soda ash will raise both the PH and TA levels. If your TA level is high, aeration is best as it will not raise the TA level at all. However, aeration is rather slow compared to the other two.

Borax is available as 20 Mule Team® Borax Natural Laundry Booster. It is sold in the laundry detergent section of most larger grocery stores and some big box stores. Borax is best added by pre-dissolving it in a bucket of water and then pouring that slowly in front of a return.

Soda ash is available as ARM & HAMMER® Super Washing Soda Detergent Booster. Do not confuse this with ARM & HAMMER® laundry detergent! It is sold in the laundry detergent section of most larger grocery stores and some big box stores. It is also sold by pool stores under various names, including PH Increaser, PH Up, Balance Pak 200, etc. Soda ash is best added by pre-dissolving it in a bucket of water and then pouring that slowly in front of a return.

Aeration can be provided by a SWG, spa jets, waterfall, fountain, return pointed up so it breaks the surface, air compressor, kids splashing, rain, etc. It can take some time for aeration to raise the PH. The higher your TA level, the faster aeration will work.

TA is raised by adding baking soda.

Baking soda is common household baking soda from the baking aisle of any grocery store. If you can find them, larger containers are less expensive per pound and easier to handle. Some larger grocery stores sell baking soda in 4 lb boxes and some big box stores have it in 12 lb bags. Baking soda can be added by spreading it across the surface of the deep end of the pool.

 

[Texas Splash]

Once you have the TA around 60-70 and the pH at about 7.2, it will be time to start a SLAM Process to kill and remove the algae for good.

 

[poolsidechic]

My TA is now at 60 and ph at 6.8, should I continue to increase a little or start the slam process? Also how do I do the slam process? Thank you so much for your help

 

[bertschb]

Also how do I do the slam process?

SLAM process

 

[poolsidechic]

I have finished the slam process. My FC is 20, CC - 0 and I lost less than 1ppm with the OCLT process. Would it be safe to swim in the pool now or do I need to lower the FC?

 

[Texas Splash]

Would it be safe to swim in the pool now or do I need to lower the FC?

Get in there! The FC will fall on its won soon enough. Congrats on passing the SLAM.

 

[IceShadow]

You need to add liquid chlorine daily to ensure you don’t go below minimum for your CYA level on the FC/CYA Levels.