I forgot about the RODI water. This is an important thing to consider when mixing new water. A marine reef tank needs very clean water for mixing salt and for topping off evaporation.Thanks so much for the response and advice!
I'm currently not using RODI water, I just used tap water treated with Prime for the water change because the lfs worker said it would probably be alright. I just lowered the pumps and 2 of the corals already look happier. I'll get more live rock as well.
An RODI filter can be a good investment if you are going to try and keep a reef long term. Some local fish stores will sell RODI water or saltwater they made using RODI water. (Pro hint- test these water sources for nitrates and phosphates, alkalinity, Calcium, Magnesium to ensure that the water you add isn't messing with your tank parameters!)
If you get live rock, that may need to be cured, especially if it was freshly harvested from the Ocean.
Also, its a good practice to put new stuff it in a bucket with an airstone, or small water pump to circulate it for a day or two and then measure phosphate. Old rock can bring a lot of nutrients that have been bound up to the rock, and it can also bring unwanted pests and diseases and other undesirable hitchhikers that can infect your tank and cause more harm than good. Removing pests before they get into the tank is good preventative measure.
Sorry to go negative, but I just wanted to put the brakes on just a little before you start trying to fix what you have and possibly make it all worse in the process.
Congratulations on the new tank! Slow and carefully making improvements is the safest way to proceed.

