Planted Tank Guru
Join Date: Jul 2010
Location: British Columbia, Canada
IMO & E., for properly maintaining any planted tank, and ensuring healthy & thriving fish, generally speaking the more frequent, and larger the water changes, the better. Primarily prevents the development of unhealthy conditions due to accumulation of wastes in these limited spaces, and replenishes needed mineral content for the benefit of livestock & plants. Smaller tanks, say under 100 gallons, will do well from receiving weekly wcs of 50% or more.
Many may argue that far less frequent wcs will suffice in a well-kept, balanced aquarium environment, but that is seldom the case in our busy lives, so the infusion of fresh new water will be always be a much acceptable mitigating approach.
It has also been shown many times over, that the higher the bio-load, the more reason there is to accelerate the frequency & quantity of wcs.
That's my .02 cents.