I realize the adding of a small amount of dry material daily is a very small price to pay for enjoying the beauty of a nice planted tank, and for most people buying a specialty pump for this isn't worth it. But there are those who simply cannot depend on themselves to follow a long-term daily routine, and for that the pump/liquid additive approach might have merit.
I make (and sell) digital dosing pumps for the reef aquarium hobby, and I've always wondered why not use a digital pump for a planted tank?? One pump I sell offers two separate, parallel and identical channels, as well as timer compatibility. It would seem to me that, set up appropriately, you could just set the pump up, set the rate and leave it alone for days, if not weeks.
That would avoid a lot of mixing of dry materials and, most importantly (to me, who often forgets) would ensure that the same amount is going in daily.
I have a planted 55 gal. tank that has been neglected for a while and I'd like to bring it back. Unfortunately, I "know me", and I simply cannot believe that I'll keep up a daily dry dosing regimen for any period of time. Just a matter of acclimating to my personal shortfall (one of many). It DOES NOT mean I don't care about the tank, have lost interest or anything else. It's just that historically I've seen myself go through "attention cycles" in which the long-term attention to detail simply is not there.
I'd like to resurrect the 55 (lit by a single 175 MH), with automated CO2 control. If it's not a lot of trouble for you to suggest a formula of grams of dry mat'l per liter (or gallon) of water and a liquid volume to dose daily, I'll set it up the pump and "rock & roll".
For a minute there I thought You were describing me!
I use per gallon of RO water:
P---20grams:1ml=1ppm/g of tank water
N--370grams:1ml=10ppm/g of tank water
K--454grams:1ml=13.5ppm/g of tank water
Fe-143grams:1ml=1ppm/g of tank water
Mg-3cups:1ml=5ppm/1g of tank water
I rarely use anything except the P and K these days. I have little to no use for the KN03--I don't know why, but I don't. The Mg is for use on Hard water (Tap) tanks, and the Iron will probably go down the sink eventually....
I dose Flourish and Mastergrow from the bottles. Sometimes one, sometimes the other, sometimes 50/50. I dose traces somewhere between 50%-100% recommended dosage--it just varies.
Also, the K above doesn't dissolve 100% in that quantity of water, so I am getting ready to cut the grams in half and just double my ml dosing on it.