As strange as it may sound, do NOT add algaecide to kill algae. Algaecides are preventative products to avoid a green pool. Once your pool turns green, add SHOCK to kill existing algae. General guidelines are to add 2 lb of a 68% or stronger chlorine shock per 10,000 gallons. If you can’t see the bottom, increase this to 3 lbs per 10,000 gallons. The same general dosages (double or triple shock) apply to Baquacil pools. You need to introduce more shock than there is algae, so this is NOT over chlorinating (or over shocking) your pool. Once the algae is dead, introduce a good, non-foaming algaecide to prevent algae from reforming. Staff at PP&P is always available to discuss your pool needs.
Here’s a great video from Poolife on what to do with a green pool.