Flushing questions

I am going to be doing my first flush for the 3 bigger plants. they are 5 weeks old and just over 3 feet tall.
I had a couple of questions before I go ahead tho. First of all, I have them in 7 gallon pots, can i get away with flushing with 14 gallons of water per pot? I know i read somewhere that 3 times the pot size for flushing, but seeing as I have to transport all the water, that seems like a bit much to me. My second question- I am going to be flushing with 7 gallons of distilled water and 7 gallons of phed aquifer water, does it matter which i use first? the only reason I ask is because right now, ph is about 5.9 which is a bit low and i think might be affecting mg, and maybe phosphorus intake. I have been getting a yellowish coloring on some of the older fan leaves starting near the veins..



Last but not least, seeing as I am going to be using 14 gallons of water, should I be using hydrogen peroxide in some or all of the water that Im flushing with? i assume that since they are going to be water logged, might be a good idea to get some oxygen in there. Thanks in advance for all the responses.

why arre you flushing these plants again??? i usualy only flush my plants 2weeks before i cut them down..

my thinking was i need to bring my ph up. its at 5.9 right now, i had what looked like a mg def so i fed some epsom salt 1 teaspoon to gallon, and didn't seem to help. that was 5 days ago. also fed them a 10-4-6 and a 0-2-2 sea kelp at 400 ppm and really not seeing any improvement. the fertilizer i am using doesnt have any per gallon rates, so i try and gauge how much im using by getting a base reading before nutes and then adding more water or nutes to adjust ppm. they are still growing, but wanted to get the ph in order before it became a bigger problem. maybe im going at this the wrong way. any help would be appreciated

Stir in a little Wood Ash or Lime. This will bring up the PH quick. Test the run off PH and Soil PH next time you water. Soil PH kits are cheap at big box stores and liquid PH kits are cheap at fish and pet stores.

1 tea spoon per gallon of baking soda will bring your ph up..i wouldnt worry about the flush,,,let the soil dry rite out so that your plants are drooping then add the baking soda and water....but as wwnugs says, most of these kits for ph are cheap.

so you think the kits are better than my hanna hi 98129 combo pen?

I dont think u need to flush just because of PH issues. Ive never resorted to that, I dont see why it wud be necessary at all. I see your using chemical nutes, thats probably whats throwing the plant off.

sorry didnt understand, what are the nutes throwing off ph?