The SeaChem Seed is simply live bacteria, and that's it. It doesn't contain whatever else is is SafeStart to help reduce Ammonia/nitrite/nitrate instantly, so you still need to use another product like Prime to keep the water safe until the cycle completes. But, it doesn't seem to ever lead to cycle crashes a few weeks in either, like Safestart is prone to do.
I have the SeaChem buffers. I've been doing a lot of research on the water chemistry, how they actually work. The acid buffer converts carbonates in the water (the root of basic water) into dissolved Co2. Which also helps the plants. There are apparently a lot of people that use both acid buffer and alkaline buffer (which adds carbonates to the water) in specific ratios for plated tanks instead of Co2 injectors and such. With the proper ratios, and knowing the pH/kH/gH of the water in the tank and the water you are adding, you can land at the exact pH you want while adding disolved Co2 for the plants. Seems counter intuitive to me, and like it adds a lot of work, but I guess it makes sense if you are going to do constant water changes and have a heavily planted tank.
I am going to start using more RO/DI water. I wanted to use a mixture of RO and tap to keep some minerals in there, but that may be too much work. Just go with the RO water and add some mineral supplement like the Discus trace you mentioned. But since I need to change out the 75% or so tap I have in there now gradually, how quickly can I safely do it? It's a 35gal, so maybe 3 gal every 4-5 days? or every 3-4?
To the lights, the Led lights do not penetrate enough for the more light demanding plants is what you are saying? Regardless of the lumen rating? What lumen rating would I need for a light in a 20" deep tank to keep more demanding plants? Do the LED lamps just not penetrate deeply enough?