Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
No measuring needed.
I use the various plant materials as decorations in the tank. I use peat moss in the filter. Bark, branches, leaves, peat moss all add tannic acid and other organic acids slowly. If the water is already soft and acidic they do not do much. If the water is harder, alkaline, then some of these materials have some exchange capacity, and MIGHT remove some minerals from the water (softening it) and adding H+ to the water (Making it more acidic). Some do this very well, other materials do not do this so much.
Measuring peat moss:
I cut up knee hi nylon stockings to make media bags.
1 whole knee hi of peat moss will prep a garbage can full of water. I use garbage cans ranging from 20 to 44 gallons, so you can see right here that the dose is not all that critical.
A knee hi cut into 2 pieces makes a nice media bag for a larger filter (canister or Aquaclear 110). So the appropriate sized filter for the tank will hold the right amount of peat moss. Tanks about 45 gallons and up get a cup or two of peat moss.
A knee hi cut into 3 pieces makes a nice media bag for smaller filters. Tanks smaller than 45 gallons get less than 1 cup of peat moss.
Since I prep the water ahead of time the amount in the filter is not enough to fully alter the whole tank of water, it is more of a stability thing. Maintaining the water the way I prepped it when I did the water change.
The knee hi full of peat that I use to prep the water lasts for several fillings of the garbage can, but toward the end I need to soak it longer. Test GH, KH, pH to see how well it is working.
The peat moss in the filters seems to last a month or two, but i have left it in even longer. No harm, but it does not do much after a while. Gauge by the tannic acid color (brown to yellow) of the tank water, and by GH, KH and pH.