depending on size of plants . small plant mix 1/3 to 1/2 dosage per total amount of water in your system larger plants mix 75% of max dosage
Add enough nutes for all 3 buckets, but make sure the nutes are added where the water is. For example, if it's a big storage reservoir that holds enough for both the other buckets, you can mix everything in the storage res. If the storage res isn't big enough to hold the water for the other 2, then prepare the buckets independently.