Still green

Hi, my first post w/forum.
Need advice on what is next step. Two weeks ago we started opening our pool 20x41 Dough Boy w/sand filter. Had to fill with a lot well water as problem with plug at skimmer over winter. Pool didn't really look all that bad just usual amount of leaves some algae. We then had numerous rain falls. We scrubbed walls & bottom, shocked pool, added algaecide worked on high PH. The debris was nicely at bottom for vacuuming. Our chlorine & PH level were high and then more rain hit again & here comes ugly algae & high PH. Several trips to pool man later and eventually got all readings perfect & added DE, pool man said not to shock & keep filtering.
We use granulated chlorine & now added 1 chlorine tab to skimmer. The pump has ran 24-7 since opening pool.
We have new liner, new hayward pump, filter & sand running 20 psi with DE added. Algae is not falling to vac, still suspended. Would love to super shock. Scrubbed again yesterday walls & bottom even with good tests the pool looks the same... green! Can't see bottom green. Perhaps with DE added in few days may clear...Just would like advise hubby has checked all he can.
Thanks for any input,
slinkie in NW Indiana