Get the filters, and save money on the color change resin and just get basic resin, and plump in a tds meter. with RO units, you need a tds meter so you know when you need to change filters etc.... A dual meter will work awesome, one before the DI and after the DI. This will tell you how well your RO membrane is, and tell you when to change your resin. It will save lots of dollars down the road. If you algae is as bad as it is, id almost say just do a black out for a couple days. I dont normally suggest those because its a temporary fix, but it will atleast get rid of some of the algae, while you work on getting your RO water up and running, and getting your lights set to good times.
As far as frozen goes, if you put tank water in a cup, thaw the cube then feed its still releasing all of those phosphates in your tank. You need to thaw with tank water, then dump that water out, while keeping the food in the container. I took the lid to a flake food container and cut just the ring part with the threads out, and hot glued some nylon screen to the lid. This holds the food back but allows the water to drain through. You can get some very small sized mesh screen that will work perfect for the job. If you do this before feeding and only feed once evrey 3 days, you will see huge improvments in your tank.
