Runoff

so I've never really cared about this... I've never had a reason to. I still don't... but out of curiosity this morning I checked my runoff pH. The pH of everything going in was 5.9. The pH of the runoff was 6.7 (after sitting in the trays for 5-10 minutes). I'm growing in 60/40 coco and hydroton. Does this sound normal? is 6.7 a tad too high? does it matter that much?

Here's a pic of where I'm at. Blackjacks... just finished 5 weeks.

My runoff is usually between 5.7 and 6

It's definately not a good thing, it means that before you pushed out that alkaline with more solution it was even higher. when your feed diluted it came out as 6.7 but you can imagine the pH inside the coco was much higher than that. I'm not sure how your supposed to combat this but I expect adjusting your feed levels would be a good way. How much are you feeding? Are you adding anything highly alkaline such as a silicate booster?

currently they are getting 7.5 ml floranova bloom, 1 ml floralicious+, 5 ml CaMg+, 5 ml liquid koolbloom, and 10 ml floranectar (and 2 ml ph up = 5.9)... I do this every three days.

prep1801 said:

so I've never really cared about this... I've never had a reason to. I still don't... but out of curiosity this morning I checked my runoff pH. The pH of everything going in was 5.9. The pH of the runoff was 6.7 (after sitting in the trays for 5-10 minutes). I'm growing in 60/40 coco and hydroton. Does this sound normal? is 6.7 a tad too high? does it matter that much?

Here's a pic of where I'm at. Blackjacks... just finished 5 weeks.
View attachment 2018540

Click to expand...

Nice looking buds. How well did you rinse the hydroton before adding it to the mix? And like the old saying goes, 'if it aint broke dont try too fix it'......

oh that hydroton was rinsed... handful by handful. When I first started growing (a few years ago) I ran into deficiencies and overdoses. I know what they look like. I don't see any problems on my plants. I'm just more curious about tweaking and adjusting things to make a perfect crop.

If your coco is buffered neutral at 7.0 depending on the brand this is normal and if your plants are not suffering I wouldn't worry about it. If you would of flushed with phed water at the beginning until the runoff was down to down to 5.8 ph it would be easier to keep it there. I had the same worry on my first coco grow and just before flower trigger I flushed with phed water until it was in the 5.8 range .This caused more problems down the road and I battled with all kinds of deficiencies . I think your ph will eventually get back to more acceptable limits once the plants start eating more nutes.

they look amazing. .. ive got 5 free blackjack from nirvanna. i know now what im growing next thanks to them pics. great job...but runoff it means jack mate to be honest. it will have you banging youre head on the wall thinking things are wrong when there far from it. its not the best way to measure you're ph ect. you're better just taking say a jug and putting 150 mill of distilled or demineralised water then adding tbs of youre medium or better to fill the jug to 250 mill of you're soil/coco mix it and sit for 2 hours then take youre ph and ec..also ph drifts are quite normal

The only comment I would make is if it ain't broke don't fix it.

An apprentice of mine never checks his run off.


The only thing I would stay away from is hydroton with coco, you really don't need any extras that also includes perlite.


Coco was designed to be used as is.

Depending upon brand of coco will depend what kind of buffers they used.

I used to pH my initial watering at around 5.5 to presoak the coco then everything else afterwards at 5.8.

You may want to add around 200ppms or 0.3EC of a cal mag supplement around now as the coco will give you a problem soon virtually all coco does this. It generally starts with an N def look to the leaves. Cal mag.



J

upon further inspection... the pH of the runoff of the other 5 plants was about 6.4-6.5. I'm betting there were some solids on the bottom of that particular tray that dissolved, giving me a higher ph reading. anyway... all is great. thanks everyone.

I would still like to know what measures could be taken if your pH for example were to come out at 8 or 9. obviously that would be a serious issue, so what would you do in this situation? I still think your pH going in should be maintained at 5,8 so any solution would have to involve changing what additives you use. Are there additives that are known to cause a downward pH drift? and additives known to cause upwards drift? If so you could possibly use them to your advantage to counter the drift up or down. What does everyone think of that idea?