I have a 10 gallon low light/tech(no co2) tank thats been running for about 3 months. It has 2 amazon swords and 3 marimo balls. I tested the water today and the results were 0 ammonia nitrites and nitrates. pH is 8. Currently there are 2 small mystery snails(about 1in) 2 ghost shrimp and 3 guppies. I am planning on letting the guppies breed to fill the tank. I have 1 seachem root tab under each sword. How often should I do water changes? Ive heard that with plants and ferts doing water changes can spur algae growth.