I don't want to rock the boat, but weekly water changes aren't a necessity just testing of your main parameters and an ato to add rodi (not tap) water. I'm only saying this as doing alot of water changes on a smaller lower stocked tank can deplete the neutrients corals use I.e. nitrates and phosphates. I'm at the stage of dosing phosphates to get my tank back on track. My tank is sump and skimmer less.
My 7 gallon tank is run on natural seawater that I do a 25% water change every 8 weeks ish that has been running for 3 years now. This was the 7 gallon back in July.
and now
this is just hammers as frags from my main tank and the the orange mushroom has doubled in size and split.
I test for all 3 of my tanks for
Nitrates, phosphates, alkalinity, magnesium, calcium every 7-10 days. Ph I dont chase the numbers for that. Temperature is on digital thermometer double checked occasionally with a temperature probe. And salinity every so often.
Just don't be put off by the learning of the nitrogen cycle, and take everything slowly.
It's a marathon not a sprint.
For my main tank I used the very old live rock from when I changed tanks from a 10yr old nano (the rock was in another tank before that) and used the excess in the 7 gal but my 3rd tank I used all dry rock and sand and even though it nearly 2 years old it's nowhere near as stable as the other 2 nor does it look as good (in my opinion) It's a fluval evo 13.5 gallon it just looks too sterile in there