My water is high 8's and I want it to be 6.8 - 7. I would like to be able to lower the Ph in the tank to start and then adjust each week when I make water changes. All the over the counter products to add to water have phosphate in them and since it will be a heavily planted tank, I don't want to use those. Since the tank is 75 gallons, I don't want to rely on RO water since that would mean lots of jugs of water to store and I would have to tinker around with the trace elements for the plants that have been removed in the process. I have heard of using sphagnum moss but that sounds again like a lot of tinkering around. I'm looking for something to add to water as I refill. I have heard also about using selzer water which, if it is safe and works, would be an option. Has anyone used that method? Has anyone found an over the counter product that does not contain phosphates? I'm new to this and want to do it correctly. Thanks for any assistance anyone can offer.