run off is ph4.8 need advice

[black_thumb]

so my old ph meter went bad, and just got the new and first thing i check is the ph of the run off is 4.8 and iv got spots all over the fan leaves.

i flushed 60 gallons of ph6.5 tap water and drip clean and did not move the ph of the run off at all. its as if the coco is now buffered at 4.8.

i dont have any silica and i have to order every thing offline. is there anything i can get at wal*mart to fix this?

 

[black_thumb]

im just going to try straight tap water ph 7.8. any other suggestions?

 

[dramamine]

4.8 isn't really that low.....over 5 should be fine. How many plants did you flush the 60 gallons through?

Drip Clean can lower ph over time, also.....is there a chance you've been using too much, maybe? RO water can cause the medium ph to drop eventually, because it has very low alkalinity. Cutting it with a bit of tap can help set the ph more firmly.

What have you been feeding them?

 

[black_thumb]

im feeding maxibloom at 7 grams, 0.5 ml of drip clean, and 3 ml of cal-mag all per gallon of tap. ppms comes to around 1100 when its all mixed.

plants are 24 days into 12/12 about 6 foot tall. showing brown, yellowing and rusty spots on the big fan leaves.

 

[danks]

get ph test strips and always double check ph pen with test strps that way you dont fuck up. ya test strips arent very accurate but they will defiantely tell you if you pen is way off or not. if everything is ok with ph pen i woul use a 300 ppm solution or 2 grams per gallon of maxi and ph it at 7 run thru till the coco run off is about 6. foliar spray cal mag solution to get rid of deficiency quickly.

 

[danks]

and by running 300 ppm solution of maxibloom is i mean feed that every day not 10 times a day. also do a ppm run off test just for shits and giggles even though with coco ppm isnt that big of a deal and testing it requires you to take a mid sample of coco frm the pot and let it soak for an hour in 7 ph water stirred then tested, at leas this is how canna does it.

 

[black_thumb]

i flushed with tap water about 150 gallons 4 27 gallon totes and got it (up) to 5.7 ph.

at the end of the flush i checked the ppm's and was around 1000.

how long should i keep feeding the 300 ppm solution?