I just finished reading a guide named something like this and for a pool man it was like reading Steven King. I've been a pool man for 20 yrs plus ,not bragging just letting you know where this is coming from. I started in the business in Florida where a pool can go green overnight in the summer. Ever pull a water sample and you can see the algae in it? Then this is for you! Trade secrets coming up!
First let me say I'm going to explain this using as little chemistry as possible. Most pool owners prefer it that in my experience. Algae blows around in the wind, is carried around on the backs of the frogs you have to net out of your pool and so on.You're not going to stop it reaching the pool so you have to do something to control it. I know someone right now is thinking I keep my pool perfectly balanced at all times and I never have a green pool. First of all well done ,but...I bet you've had yellow algae. See what I mean it will get to the pool . People who keep their chlorine up all the time get yellow algae, green algae with the color bleached out because it has adapted to your chlorine level. Here are the steps I use myself to turn a green pool back to blue. The last one I did, 3weeks ago , was blue in 72 hrs.
1. Test your pool water, if it's green your ph is probably 7.9 or higher. The higher your ph the less effective your chlorine will be. Read the last sentence again it is super important. When balancing pool water always adjust alkalinity first.......but when fighting a green pool adjust the ph first . Drop it down to 7.2 -7.4 This will make the chlorine much more effective .
2.Add chlorine- How much?- I use the chlorine to help burn off the algae's food -phosphates mostly- and yes to stop the algae's capability to bloom. You should test your water and check your free chlorine and your total chlorine. These numbers should always be the same. When they aren't you need to 'shock' your pool. The amount of chlorine you need is the difference between the two readings x 10. Example 3.0 total chlorine 1.0 free chlorine =add enough to raise the chlorine level 2x10=20ppm. Check your charts to see exactly what that amount is -contact me if you need help.
3.Here's the good part! When you actually get to kill the algae. Buy a good quality copper based algaecide. This products label will say something about elemental copper in its percentage area.It should be somewhere around 7%. There are numerous brands. A note about algaecides- I never buy or use any algaecide (with the exception of copper based) that is not at least a 50% poly-quat. The algaecides that come in a gallon jug are usually quat algaecides not poly-quats.Quat algaecides will foam up your pool if you over dose them and they don't really kill algae they just make it harder for it to grow. Add your copper based algaecide to a bucket of water. It will be very blue and if you get it on you, your pool deck , your cloths you /they will be very blue also. Pour the bucket of blue death( to algae only it won't kill you ,just turn you blue) around the pool with the system running. Copper disrupts the way the cells in the algae work and it does a great job of killing that stuff . The algae should die and fall to the bottom of your now clear and blue pool. Make sure you vacuum to waste to remove the algae from your system , if you have a cartridge filter and can't vac to waste then clean the cartridge as soon as the flow starts slowing down.It may take multiple cleanings no matter what kind of filter you have. Clean your filter whenever the pressure on your pressure gauge raises 6-8 pounds.
4.Balance your pool water . Bring all levels back into line. Alkalinity 80-120 PH 7.4-7.6 Chlorine 1.5-3 Stabilizer(cynauric acid) 40-70. Calcium should be adusted following pool builder/manufacture's suggestions-different surfaces require different amounts .
SOME HELPFUL HINTS
Never add cholrine tablets directly to your pool-they have a ph of about 2 so even in a concrete pool they will do damage.
Always add chemicals to a bucket of water-never add water to chemicals. The theory being if you pour something into something else it displaces what it's falling into .Pour chemicals into water what splashes out should be water and vice versa.
Never mix pool chemicals!!!!!! Granular chlorine and 3" tabs of chlorine can cause an explosion if mixed together. Treat chemicals with respect and read the label's warnings. Keep pools what they are supposed to be FUN! I hope this has helped ,if you need pool info or parts you can find me here on e-bay at L and E Pool and Patio