Weekly water changes??

So it's been 3 weeks since setting up the main display tank (90G with 55G sump/refugium). Moved existing live rock and live sand from holding tank into MDT. It was kept alive along with 3 cucumbers. Water parameters have been perfect since set up.

Have been ghost feeding for 2 weeks. Ammonia, Nitrite, Nitrate, Phosphate still all at 0. Calcium at 460. PH at 8.2. KH at 10. Inertebrates added almost 2 weeks ago (snails and crabs). All doing well. Macro algae also added then (red mangroves and Cheato). Ugly tank algae really on the decline and the tank is looking good!

Now my question. I've done a water change each week even though water parameters are great. Water is clear. Do I need to do a water change weekly, even when everything is looking good? Haven't added any fish or coral yet as I've been being patient to ensure the tank is ready. Bio load is obviously very small except for my ghost feeding every other day.

I don't want to do more work and spend more money than necessary, but also don't want things to go south and am happy to do the water changes proactively. What do you think, considering all of the information I've shared about this tank? Looking to add first fish next week. (still not sure which fish to start with...)

Thanks and Merry Christmas!!!