I have a 55 gallon planted tank that has been up and running for about 3 weeks now. It has 10 Vallesneria and six Amazon Swords. The Vallesneria are in a melting stage, but there is some growth coming back. The Swords looks as good as they did when I received them and the roots are growing quickly. I added root tabs last week and have been doing weekly 20% water changes, after which I add 5 mL of a liquid fertilizer (Aquarium Co-op product). There are currently no fish in the tank. I have 25 fish in multiple quarantine tanks that I need to transfer in the next week or so. The QTs get water changes every 2 days. I've read online that it would be a good idea to start using the water from the main tank for my quarantine tank water changes. Seems like a good way to get the new fish acclimated to the main tank conditions. However, I'm a little concerned because of the melting Vallesneria and also the amount of dissolved solids in the water (because of the fertilizers). Is this a valid concern? If it is advised to use the main tank water for water changes, it seems like I should use a very little amount of it at a time. Maybe no more than 10% of the quarantine volume at a time? The two quarantine tanks I have are 20 gallons, and I change about 1/3rd of the quarantine volume at a time, so would 2 gallons of main tank water and 4 gallons of fresh tap water be a good WC ratio?