Hey Kitty, you say 5ml per gallon, so i have a 55 gallon res. but only use about 35 gallons so i should be using 165ml every 3-4 days seems outrageous to me. I been using 2 caps full thinking i was doing just fine.
Remember that the usage amounts will vary depending on the concentration. WE use 29% H2O2 as most hydro stores sell...... For that, the jugs say "3mL/gallon"..... For your 35 gallon reservoir, you should be adding 105mL-ish to the reservoir every 3 or 4 days. I do ours on Foliar days so I remember when I did it..........I use 5mL/gallon, using even 10mL/gallon wont hurt your plants. There probably isnt a huge benefit either to using the extra 2mL/gallon, but I'm one of those "play it safe" types of growers.....
The little rite-aid and walmart bottles have a stronger dillution, may not have an inactive ingredient of water, and isnt really even the same H2O2 that you would use for plants..... I would advise not going this route and to go the "meant for hydro" stuff........
And by the way permat, if you fill your res full instead of 20 gallons short each time, you'll find your ph and ppm drift a LOT less..... Makes for easier nutrient topoffs, less water topoff attention, and a more stable big batch of solution for your plants..... Max res size always!
You add x/ml/gallon as the jug indicates. I dont know how big your reservoir is, but you'd use the basic math yep! BUt you add it every 3 or 4 days, not every time you do something nutrient specific.