Adding an another PH
would be a good idea as the canister will not really provide sufficient water movement. I would also suggest raising the SG
to a more natural level, 1.024-1.026. The lower level may lead to future problems as you begin adding animals to the tank. Once the heater is in, set it to 25-26°C and then tweek it until you get a thermometer reading of close to 27°C (80°F).
If the LS
is unopened, I would return it. Unless it is sand from an established tank or loaded with fauna, they are a complete waste of money. I would instead suggest reading about "How to cycle your tank with out the use of fish
". It will do much the same thing and save you alot of money.
The amount of rock to add is really up to you but the more the better within reason. The general concensus is 1-˝lbs/gal
of tank volume.
What type of tank are you planning on? FOWLR