Currently using Seachem Equilibrium (and their acid and alkalinity products as well) and getting about 4.8 GH and 3.4 KH (and shooting for a pH of about 6.5). Would a GH of half that be bad for plants? Should I stick with the formula I am going with now or is it safe to go lower without any negative impact?
No stem plants really and I doubt I will be adding any in the future. Mostly stuff like Cryptocorynes, Anubias, Echinodorus, and Aponogetons.
I have been enjoying following your latest tank set ups.
As I recall you have always done pretty well growing plants. I would not over complicate remineralizing RO water. And with your mix of plants, honestly they are much less sensitive to KH/GH levels than a tank full of stems.
First of all I am not sure why you are using the Seachem products. With your multiple tanks, you are much better off purchasing dry salts and making your own mixes. Not only will save you money, but you can fine tune much easier and only add what you want.
Let's start with GH. Most planted tankers I know shoot for somewhere between 6 to 8 GH, at a ratio of Ca:Mg between 3:1 and 2:1. All you need is CaSO4 and MgSO4. Seachem equilibrium is basically the same thing plus K. And you may not want all the additional K. With your mix of plants, honestly anywhere in those ranges is fine. And lower might be fine too, but not sure why you would want to??
For KH, your RO water should be at zero. You can raise KH (and pH) by using K2CO3 or KHCO3. Most plants prefer softer water, so KH of 1 or even less than 1 is fine.
You said you are shooting for a pH of 6.5?? Why? Regardless should not be very hard to get to. If you dose to 0.5 KH, your degassed pH should be somewhere around 6.5/6.6.
So like I said, pretty simple......a little CaSO4, MgSO4, and either K2CO3 or KHCO3 and you can get to any KH/GH/ph you like.
Anyway, like I said have been enjoying your journals. Looking forward to seeing future updates and pics.