Why is WC important for FW tanks?
What is the purpose of making WC?
Relating back to the reefing days, we do WC to lower NO3, PO4 and to bring ionic balance back closer to normal.
Even for FW fish only tanks, we do WC to keep NO3 and other dissolved nutrients down to prevent algae bloom. Since typical fish only tanks there are either no plants, or little plants to make significant impact on nutrient level, so it's natural that these systems require regular WC.
But, planted tanks on the other hand do not have enough nutrients to start with. We typically has low fish to gallon ratio, and we have to keep adding NO3 and PO4 back into the water to keep these nutrients level up high. In that case, shouldn't we do less WC? I can understand the importance of WC for immature tanks such as during new tank setup. But for established tanks, is large and weekly or bi-weekly WC still necessary?
It just seems we are working backward by dumping ferts into the tank every day, and dump a big chunk of them out into drain every week or so.
For those that do WC, why do you do it?