Thanks So much Pat.VaughnH;33794 said:Don't forget that what is in the bottle is water - plus a tiny bit of fertilizer. Buying water isn't a great idea, even if you plan to drink it, and you wouldn't drink liquid fertilizers. So, just buy KNO3 and KH2PO4 from:
Planted Aquarium Fertilizer
Planted Aquarium Fertilizer | Green Leaf Aquariums
or other online stores. Then put your own water in a bottle, add a tiny bit of those two chemicals, and you have the world's best liquid aquatic plant macro fertilizer, at the world's lowest price.
To figure out how much water and chemicals to put in that bottle, buy a bottle like this: Fertilizer Dispenser | 500 mL (16 oz) | Green Leaf Aquariums, or 16oz fertilizer bottle: Containers - 0008-EB16 - Oregon Aqua Design - Your D.I.Y. planted tank store!. Those hold 16 ounces, and you would want to dose one ounce at a time for convenience. That means the bottle holds 16 doses. If your tank requires 1/4 tsp of KNO3 per dose, add 16 times that to the bottle (4 tsp), and if it requires 1/8 tsp of KH2PO4, add 16 times that (2 tsp) to the bottle. Fill the bottle with water and shake it up. You are then ready to dose.