The tested TDS of 650 ppm or 1300 µS is a clear indication of a serious water column mineral problem. The usual water column value with RO water is ~ 100 – 150 ppm or ~ 200 – 300 µS. Personally, I had many continuous water change setups and they did not work as well as water changes spread to longer periods of time. If your logistics allows you could consider changing 25 – 30 % weekly at once.
One of the problems with this 1 gallon per hour water change is Ca consistency. At first it doesn’t look like much, but after a week, 70 % water has changed and Ca concentration drops to 30 %. Plants can’t handle this easily. All other water level parameters can be dosed, except Ca. There is no Ca compound that can be concentrated enough to be used with liquid dosing pumps. We have no other option than add dry CaSO4. I would be adding once a day 20 ppm Ca per new changed RO water, that is 24 gallon, 7.8 grams.
It is clear that we cannot use the GH Booster because with 20 ppm Ca, it adds 40 ppm K and 8 ppm Mg. It is simply too high.
For KH I would use 1 dKH with NaHCO3 baking soda, because it is easy and contains beneficial Na for plants and fish. It needs to be dosed daily. It is important for the CO2 controller to have stable KH. Right now, you have KH fluctuating from 100 % to 30 % in a week which results in CO2 levels sinking from 27 to 8 ppm CO2. Not good, plants will complain.
day 1 => dKH 4.50 => 27 ppm CO2
day 7 => dKH 1.35 => 8 ppm CO2
For Mg I would be dosing daily 5 ppm with MgSO4 per new changed RO water, 24 gallon. And then there is no need to add MgSO4 to the PPS-Pro solution.
As for the light, don’t limit intensity, limit time period. It can have 200 PAR but fewer hours.
You said you have detritus build up. That is what BBA goes for, dissolved organics. Filters need to be cleaned as often as dirty. And you need snails for cleaning periphyton from plants and other surfaces.
Can you explain how you derived those ppm calculations? That's a vast difference in levels. I can switch the dosing to occur once every day before lights come on, do you suggest this?
My first scenario is wrong, I mixed gallons with liters incorrectly.
High Light PPS-Pro daily dose 2 ppm NO3
Aquarium 250 gallon
# of doses 24
Water change 1 gallon
Water change per day 24 gallon
2 / 24 * 250 / 1 = 20.83
2 * 250 / 24 = 20.83
The final limiting concentrations are:
I would change the PPS-Pro dosing to 50% for both solutions.