Hello from Montreal!

[AnnaK]

Hello Nick, welcome to the Pool Forum.

May we please ask you to complete the

Pool Chart Entry Form
Pool Chart Results

That gives us the info about your pool all in one place.

Your vinyl pool doesn't need calcium so you can use plain bleach to shock, or use dichlor granular shock. The latter will also add CYA (stabilizer) which you do need and should bring to around 50 ppm. The floater you're using will also add CYA.

How are you presently testing your water?

Dichlor and trichlor will drop the pH a little. You said you added 'Alk' to raise the pH. What, specifically, is Alk.? Can you get 20 Mule Team Borax, or Washing Soda? Zeller's or Loblaw's might carry those products. Borax will raise the pH nicely, Washing Soda will also raise the alkalinity some.

Keep adding the 10% bleach and yes, your instincts are correct: add it at night to avoid losing it to UV light. Although, if your weather is like what we had in Ottawa over the weekend, there's not much sun to break down the chlorine right now. Add the chlorine until the water isn't green anymore, or–if you have a good test kit–until your overnight chlorine loss is less than 1 ppm.

Don't put in any algaecide just now. The high chlorine level will destroy it. Spend the money on bleach, instead. Keep the pump and filter running, backwash/rinse as needed.

We'll help you defeat the Green Monster