Why has my Ph droped?

[cwesto]

SA, do u think that if i implemented bush doctor sledgehammer by foxfarm into my feeding schedule it would take care of this problem??

[whatsthatsmell]

you can use tap water that hasnt been sitting out....i do all the time and have no problems (well currently, i did before because i followed the label on some nutes and burned them). Your really not doing all that much by leaving it sit out, yes, it will bring the pH down some, but its not gonna be enough to worry about. You need to keep flushing those plants until the water coming out of the bottom of the plant reads 6.5 - 6.9, after that is completed you plants will return the love in about 24 - 48 hours (you should see a difference that quick in soil) You dont HAVE to repot, it is recommended, but not a necessity, you will just have to remember to watch that soil pH closely.

[organic_sourdiesel]

Well, the reason I always let my tap water sit overnight with bubblers is to get rid of the chlorine that the city puts in it, not for the ph to move...

I mentioned in another post that I have had lockout/salt buildup before, and once I used the hose to keep flushing my 3 gallon pots, as it took amazing amounts of water to bring the ph up to 6.0. Even after doing this, my plants were deficient and never recovered, resulting in them finishing early by 3 weeks. This happened a second and third time. (sheesh!) The second time, I flushed, then with the pots still soaked, fed them a medium strength mixture. This did not work either. They kept getting more and more pale with lots of yellow dying leaves, and the plants finished early by about 2 weeks. The last time when it happened (I'm always putting in ph6.3/6.4 btw), I flushed them and then fed them, they were still yellowing, then I gave them cal-max, and they greened up again and the leaves were perfect until the end. Perfectly straight and a nice medium green. So it worked, but they were still bolting (finishing) already, and finished a couple weeks early. Every time this bolting has happened, the herb has been top quality, but the buds small, and plenty of "popcorn" bud... I've only been getting like 1/2 Lb per 1000watts.

So I'm worried about flushing away the only nutes left in the soil, but I'm also worried about lockout setting in. I'm thinking that it just might be a good idea to flush them hard tonight until the runoff is at least 6.0 or a bit higher. Then it will take about 4-5 days for them to dry out before I can get food to them, so this might contribute further to any kind of deficiency. They are looking paler in all of the new growth now... As I asked before, does anyone think it is a good idea to foliar feed them with this:
pbp grow 2.5mL/gal
pbp bloom soil 2.5mL/gal
should I add some calmax?
this is about 200 or 250 ppm (don't remember exactly, but around there)
I have this solution ready in my sprayer. I made it weak as the plants were overfed initially, but they really do look like they are lacking a bit now... I was going to apply it right before the lights turn off. good idea?

After all this, when I get back to regular feeding, I'm feeling that (botanicare nutes which they say to use every watering), I should only feed at 1/2 strength, and maybe only every other watering. Thoughts on this? Perhaps even less? their recipe goes up to like 25-30mL/g, and this seems way to high for diesel, which is pretty sensitive, being sativa predom...

My setup:
- 1000 watt hps x 8, four of which are air cooled
- lights are 18" above plants on average
- 78 1 gallon pots on four tables
- 3 oscillating fans
- drain tables on sawhorses with pond liner and drain lines
- room temps: day(light): 75-80 night(dark): 70-73
- room %RH: low... 30-35 (this is not the cause of my leaf fringes curling up. That has never happened before, and I grow in the summer and winter. I've been in this house for 4 years)
- large carbon can on exhaust. exhaust is on a switch, which is connected to a motor control so the fan switches to lower speed at night and the intake turns off
- 100 gallon res with four air stones and two aquarium heaters
- tri-meter ph/ppm/temp (the best, IMHO) properly calibrated
- 2 1500 watt heaters for dark time
- 400watt MH with 4 young mothers
- 2 sulfer burners in case powdery mildew sets in (then use 1 hour per day, which works great)
- 1 6 burner CO2 generator, which runs on a standard barbecue propane tank (not used until week 2 of bloom)
- organic sourdiesel week 1 bloom.

I have a very nice setup and perfect conditions. Perhaps a little more humidity would be nice, but it is not causing any problems. I have been growing for like 8 years, but am fairly new to soilless, and it has been giving me problems. We were having trouble keeping water temps down for the bucket hydro system, and switched to soil for the "forgiveness" of it. Just seems that all the nute companies instruct you to overfeed. I've used
GH, Advanced, back to GH and now am with Botanicare (I want to be organic). This seems to be the case whether we keep our girls small in 1gals or go bigger in 3gals. One of the best rounds with the diesel was when ever other watering, we were flushing 6 gals for every plant. This was WAY too much work. I've discovered the key is to not soak all the soil when you feed. Just a small bit that only gets the top wet, then twice as much water on the next irrigation.

Well... that's a lot for now. I'm hoping to give a complete picture of my setup and problems and experience. Perhaps I should start a log...

one love

Here is my first thread:
http://boards.cannabis.com/indoor-gr...ce-please.html

[stinkyattic]

The last step in the flushing process, if you're not harvesting within the next week or so, should be a heavy watering with a nute solution that is pH'd and at about 1/4 of what the manufacturer recommends. That should avoid deficiencies that were caused by removing the available nutes from the soil.

[saltypimp]

hey cwesto -

You r problem is usinf pro mix "HP"...it has a range of ph, i believe, 5.3 to 5.7 out of the container it was sold in (somewhere around, not #, but forgot) use the pro mix "BX"... it has a range of 5.5 to 6.3 out of the box i believe...

just add some extra perlite and you got yourself some "HP" using "BX"... you should be adding extra perlite anyweays so why not just get "Pro mix BX" and add some perlite, and what do you konw, you got some pro mix HP ( with added vermilculite, dont like this, but its better than havinf ph issues... never had problems with BX, but with HP had promblems.... hope this helps!

( i rerad this off a fourm, and tested myself what the soil ph waas on these hp and bx right out of the paltic containers they were housed in)

[saltypimp]

out of the containers (brand new) runoff ph:

"HP - 5.2-6.2 PH"

"BX - 5.5-6.5 PH"

Use BX, much easier to use and control ph...for me at least