The factory instructions are to mix up a gallon kit of LPD as usual. You take 1/3 of the gallon and mix it with water 1:2 for one gallon of working solution.
You take the remaining 2/3 and mix it 2:1 for one gallon, which becomes your replenishing solution.
For each Qty 30 - size 8x10 prints (or equivalent), you replenish 300ml.
At the end of the printing session, top up your working solution to fill your storage container completely.
When you run out of replenisher, you mix a new batch. But here is where I do it differently than what's recommended; I use the old working solution to mix the new working solution instead of water. So 1/3 of the fresh LPD is mixed with old working solution to make one gallon of fresh working solution.
I think I've gone through maybe 30 cans of LPD and I have continuously replenished the same LPD this way every single time, so there is some trace from the very first can in my existing working solution.
I honestly don't know how other replenished print developers work, if there's a specific replenishing solution, and so on. But that's how LPD has worked for me, and I really enjoy how it's working out for me. Very economical.