P-Up is not a must need type of thing.You might want to look into an auto doser,so you can't forget to dose. That's how I dose my part A+B controled by an Octopus 3000,so as my corals grows the Octopus3000 automacticly up my dosing to the needs.That's not the only thing it control(temp,P.H,alk,opr,magnesium,strontium,iodine).It's pretty exspensive but it cuts my work down to almost none. all I really have to do is feed my fish and check on my cpu to make sure the Oct3000 gets all it need to matain my tank.Everything I dose,I buy in 5 gallon bucket so I only check about twice a year.But like i said it's very exspensive,but you can always dose by hand.