I wouldn’t do a super large volume flush, but that’s just my opinion. Obviously I don’t know anything about your tap water, but I can say for sure that I wouldn’t use my tap water for this if I were doing it. It has way too high EC/TDS and the pH from my tap is close to 8.0. That’s why I recommended using your distilled water with some cal/mag as a buffer.
Before I started using RO water I used to have trouble with residule alkalinity because of my tap water being so high. If you know your tap water is better quality than mine, that’s a different story, but if it sucks like mine does, or if you just don’t know, I’d be careful.
I don’t think the idea of your flush should be to change the soil pH, just to rinse out the last feeding with a low ppm, proper pH’ed solution, and then resume feeding as normal the next time she’s thirsty.
My tap water is high iron well water, I’ve never had it tested , dogs drink it we shower and do laundry and dishes with it, I brush my teeth with it also. But I’m afraid it might have some kinda bacteria or something that would kill plants.
I went bought 12 gallons of Kroger’s drinking water it’s PH—57.6 when first opened, I’m leaving the lid off it see if it changes, if not I’m gonna just flush each plant with gallon that straight up, or do you think I should add anything or raise PH a tad more,I have ph up and down
Chances are if you’re talking about bottled water it’s just as void of minerals as RO/distilled, so the same advice from above still applies. You’ll need to add a buffer before you can get a true pH reading or make any adjustment.
I used krogers gallon jugs just called drinking water ,PH I think was like 5.7
I added PH up and got a gallon for each plant at around 6.7 , then poured on each plant .
All runoff’s were like PH 6.2–6.2–6.1–5.8 runoff PH.
Then cal -mag same drinking water gallon , and a very little lotus boost , used PH up till about 6.7ish. Split the gallon between all 4 plants hopefully look better in morning, lights on all night. But for now on my Ph will be adjusted after all nutrients are in water first. Try keep it around 6.5–6.7
I ph upped just Kroger’s gallon drinking water to about 6.8 , gave a gallon to each plant , and runoff was 5.8 6.1 6.1 6.2 so I’m thinking where I was feeding them straight distilled water with my mixed nutrients caused this problem, I’m switching back to using the drinking water instead of distilled or either, but I’ll mix nutrients first and then adjust PH balance for now on. I wasn’t doing that I just mixed shit up and fed them. I’m hoping they all come back to good life , they were not completely shot yet.
Good deal Grow Bro, they’re looking good and just below the PH uptake range of 6.3-6.8 
They are hungry
I think I over fertilized the plants , they still look ok , but not as healthy as they could be. So today I used just a touch of Lotus Boost, as a kinda buffer for Kroger’s gallon drinking water. Brought the PH up to around 7- to 7.18 with ph up ,used all 4 gallons on the 4 plants, quart at a time each plant so as to distribute the different ph water.
The runoff after a gallon each was like 6.3-6.5 all but one was like 5.8 maybe, and it’s the most affected plant. In 3 days I’m gonna do the same again and just a touch of boost and see what they look like, this indoor non auto flowering plants are tough, especially winter temps and humidity, think I’ll just stick with auto flowering indoor winter and fall
and summertime just grow me 5 or 6 girls outside.
Sup growmie. Your girls look great. It is perfectly normal to have some leaves turn and be consumed by your girl during flower. Make sure your runoff numbers during flower are between 6.5 and 7.0. The nutrients she needs during flower are best used at this range PH. I promise you when this grow is done you wont go back to autos. I used think autos were the way, but photos is what you want. In my experience, i get a hell of alot more yield and potency out of photos. Plus you can HST and LST photos and have time to recover where with autos you really cant. You have control over your girls with photos and not with autos really. Autos are too unpredictable. Are you checking PPM with a TDS meter? @BigJer
do you have run off PPMs to substantiate this? A few/several Lower yellow leaves mid to late flower never concern me but mid to upper usually lead me to believe a deficiency that could be related to PH being out of range for nutrient absorption or just plain hungry and not being fed enough
yep…this