I have green algae.... and it wont go!

[HappyHippyDad]

Hello everyone.

This is my first post, so hello to everyone

I have had my above ground pool up for around 3 months and it has been fine. 3 days ago it looked cloudy and there was green stuff on the bottom of the pool. I swept the green stuff off the bottom and now the whole pool is green.

I vacuum it once a week.
The pump and filter are going 8 hours a day, from 10am - 6pm.
I back wash and rinse the sand filter every 5 - 6 weeks, the pressure is always ok, around 0.1 psi
I'm fairly good at keeping the free chlorine between 1 and 3.

The pool is below a tree. Leaves fall in it every day. I take them out every day, but there is always a build up of debris in the bottom which gets hoovered out once per week.

I have tried shocking the pool by putting in 84g of stabalised chlorine granules, I did this yesterday, it has made no difference.
I have also put in 30ml ultima plus pool and algae remover with no effect so far.

PH = 6.8
CY acid = 0
Free Chlorine = 2
Total Chlorine = 10-15
Bromine = 10
Total Alkalinity = 60

My pool size is 4.5m x 2.2m x 0.7m

I use a bestway sand filter pump which i think is suitable for a 3028Litre pool. I know I did all the calculations at the time in order to buy the right pump, but doing the math again it looks like my pump/filter is too small as my pool volume is almost 7000L. Have I got this right?

I hope I've given you enough information.
Basically, I want to know how I can get rid of the green stuff?

Many thanks

[basus89]

Shock your pool with a higher chlorine dose to kill the algae. Raise your pH to 7.2-7.6. Run the pump continuously and clean the filter frequently. Consider upgrading your pump since it might be undersized for your pool.

[Teapot1]

Shock your pool with a higher chlorine dose to kill the algae. Raise your pH to 7.2-7.6. Run the pump continuously and clean the filter frequently. Consider upgrading your pump since it might be undersized for your pool.

You talk a lot of nonsense!
Same applies to all your answers

[HappyHippyDad]

Shock your pool with a higher chlorine dose to kill the algae. Raise your pH to 7.2-7.6. Run the pump continuously and clean the filter frequently. Consider upgrading your pump since it might be undersized for your pool.

You talk a lot of nonsense!
Same applies to all your answers

Hi,
Would you be able too give some advise on the problem please?
Thankyou.

[Teapot1]

Hi, no problem. Lets start with your test results, sounds likely you are using dip strips? These are at best a guess and although you see the strips change colour they are very inaccurate. Bromine you are not using so discount it but chlorine would normally be 1/2 the bromine measure. Your free chlorine 2 but total chlorine 10-15 is possible but unlikely, it does show you have combined chlorine that you don't want. The CYA is zero which it can't be if you regularly use pucks and just added 84g of shock. Now almost all packaged products contain stabilizer (CYA) and this builds up in pools even after just 3 months and it reduces chlorine's ability to sanitize the water. Although you added shock, shocking a pool is a process and not a product. It means raising the free chlorine level by any addition of chlorine and holding that high level until you burn out the combine chlorine so your total chlorine equals your free chlorine. I would use liquid chlorine bleach from a hardware store, strength of the chlorine varies but 9.6% is usually
available or pool shop if you must. This is unstabilised chlorine so won't add to you CYA level. At 7000ltrs I would add 2 liters of the 9.6% to start with and the water will turn blue grey and cloudy, this is dead algae. You then add more chlorine as necessary to maintain the high chlorine level for a few days until the water clears and total chlorine as equal to free chlorine +/- 0.5ppm. Then you are done shocking. Don't waste your money on algaecide, it doesn't work unless its copper based and that can stain. Don't worry about your pH at the moment it will go high due to the high chlorine content but will subside as the chlorine gets used up. Afterwards you can adjust if needed. If you can get a proper test not with strips done at a pool shop for now you should so we can see an accurate picture of your levels.
Good luck and pop back to see how you are getting on. Best not to swim whilst heavily shocking the pool.

[HappyHippyDad]

Hi, no problem. Lets start with your test results, sounds likely you are using dip strips? These are at best a guess and although you see the strips change colour they are very inaccurate. Bromine you are not using so discount it but chlorine would normally be 1/2 the bromine measure. Your free chlorine 2 but total chlorine 10-15 is possible but unlikely, it does show you have combined chlorine that you don't want. The CYA is zero which it can't be if you regularly use pucks and just added 84g of shock. Now almost all packaged products contain stabilizer (CYA) and this builds up in pools even after just 3 months and it reduces chlorine's ability to sanitize the water. Although you added shock, shocking a pool is a process and not a product. It means raising the free chlorine level by any addition of chlorine and holding that high level until you burn out the combine chlorine so your total chlorine equals your free chlorine. I would use liquid chlorine bleach from a hardware store, strength of the chlorine varies but 9.6% is usually
available or pool shop if you must. This is unstabilised chlorine so won't add to you CYA level. At 7000ltrs I would add 2 liters of the 9.6% to start with and the water will turn blue grey and cloudy, this is dead algae. You then add more chlorine as necessary to maintain the high chlorine level for a few days until the water clears and total chlorine as equal to free chlorine +/- 0.5ppm. Then you are done shocking. Don't waste your money on algaecide, it doesn't work unless its copper based and that can stain. Don't worry about your pH at the moment it will go high due to the high chlorine content but will subside as the chlorine gets used up. Afterwards you can adjust if needed. If you can get a proper test not with strips done at a pool shop for now you should so we can see an accurate picture of your levels.
Good luck and pop back to see how you are getting on. Best not to swim whilst heavily shocking the pool.

There are usually little emojis to say thankyou etc.. I can't find them, so just writing back to say a big thankyou for taking the time to explain it to me in a really thorough way. Thankyou

[Teapot1]

No problem, just please pop back as I make it sound easy but it can take a few days and time isn't available from a pool store.