Hey bro I bought the exact same tank as you 6 weeks ago! Oceanfree Tank black color from c328 auntie for $65.
I cycled the tank for 2 weeks with all the stock filters and tap water and some 2nd hand salt and LR.
I tested the water with nitrate testkit (only have one testkit) which shows zero and after that I introduced a $1 clown into the tank and shrimp and tubeworm. they are still surviving till now:)
I first installed a 0.14ampere 2" fan on the cover and managed to keep the temperature under 30 degrees But in recently weeks it escalated to >32. So I install another 0.34ampere 3" fan but the temperature still hovers around 31 in the hot afternoon.
I have 2 pieces of rock with mushrooms and yuma and they are doing good so far, but last week I bought zoas and it never open and decay and I have to toss them away.
Anyway so far I only changed the sponge twice.. Just check and feel if dirty just change new one.. I bought the sponge for like 3bucks at some LFS cheap cheap.