Help with pH

[Oilers]

I have a 150G tank and I have 2 cleaner shrimps, 2 fire shrimps, 30 hermit crabs, 10 snails, regal tang, yellow tang, sailfin tang, copperband butterfly, 2 percula clowns, 2 black clowns, coral beauty, naso tang, 2 chromis. Picked up a cleaner shrimp from Steve. Looking to add a flame angel later this week.