Salt build-up in late flower: SOS, Help!

[King Tubby]

I will try and get a pic up later. Details below.

After numerous misdiagnoses of deficiencies, ends up I have some serious salt build-up: numerous deficiencies, purple, yellowing, browning leaves, stunted growth on lower nodes, etc. The MAT is purple and wilting like crazy. Looks like it's dying. The Power Plant is yellowing a little, and the Haze has some yellowing, older fan leaves

I have some mediocre sized buds. With an estimated 10 days left, is it safe to flush with just straight tap water? Am I cutting off nutes too soon? My concern is that the girls look like they need to bulk-up some, and I'm worried about cutting off nutes entirely.

PPMS climbed ridiculously high (2000) but these are plants vegged for 3 months and are massive! Three take up like 40" square. They handled the nutes fine with some minor burn until mid flower.

The haze will take longer: can it tolerate being flushed in the same channels as the other two for a few days?


What STRAIN are you growing? Menage a Trois, Power Plant, Haze x Skunk
What was the establishing technique? Seeds
What is the age of your plants? Seeds started on September 9, 2007
What PHASE are the plants in? 50 days into flower
What Technique are you using? NFT with stream, not sprayers
What substrate/medium are you using? Hydroton
What is the Nutrient temperature? between 60 and 72
What Nutrient's are you using? PBP, Calmag, LK, Hydroguard
What is the TDS/EC/PPM you are using? flushing now, jumped to 1800 ppm (.5 conversion). Tap water in reservoir jumps to 700 ppm next day!
What is the pH of the "Tank"? tap pH adjusted to 5.5, climbs to 7.2
Are you sure your calibration is correct on your equiptment? Yes
When was your last watering? Filled up reservoir with clean water last night
When was your last feeding change? started flushing two days ago
What size bulb are you using? 600w HPS
What is the distance to the canopy? 12"-18"
What is your RH Factor? low 30s, lately around 40
What is the canopy temperature? mid 70s lights on
What is the Day/Night Temp? 74/60
What is the current Air Flow? 6" vortex to carbon scrubber, fan aimed at floor
Is the fan blowing directly at plants? No
Is your water HARD or SOFT? 30 ppm

 

[MynameStitch]

You want to flush at least a week with just plain tap water, yes it will rid the salt buildup in the plant when you flush properly, your plants should be at least 5 feet tall before feeding them that dosage man, that is hella high ppm's.....

What was your pH like? Did it go up more or did it go down more? When you had all those high PPM levels in there...... How often were you testing your pH through the grow? Did you calibrate it every 2 weeks max?

 

[King Tubby]

pH gradually climbed and sat around 6.3 in flower. I'd let it float around a little since pH down (the Earth Juice citric acid one) seems to not hold well.

I have a tri-meter: pH and ppm were checked daily. I think I didn't flush when I swapped out my rez water and upped the dosage.

Plants were 4 and 1/2 feet tall man! I stepped up the dosage gradually but burned them some in mid flower.

I know the dying leaves will die, but do you think they'll pull through and swell some? Bud growth on the PP and MAT is severely stunted (overfert) but the Haze is looking fine: funny cause I thought the Haze was a light feeder traditionally.

Live and learn: I got some nice shit ready to go in there!

 

[HeadyPete]

You should get a lot of bud growth in these next few weeks. This is when plants pack it on, almost dramatically so in some cases. Make sure to let them go as long as they need to finish. Never mind what the package says.....50 days is a little over halfway for alot of strains, but you do have a good strong light and NFT, so that time should come down. Make sure to harvest when the trichs are about 20% amber, give or take depending on preference. Only pick the buds that are ripe, leave others to continue swelling and ripening. This ensures you get maximum yield from your plants.

Your ph will rise naturally as plants take nutrients from the rez. This is why constant checking and adjustment is important to keep ph as stable and ideal as possible, before it swings out too far. Plants don't like that.

 

[Weedhound]

I agree with the first two follks....Stitch is right.....what's with that 2000ppm at a .5 conversion? Just how badly did you burn these plants with that number? And 6.3 is just a TOUCH out of range...not bad ....6.2 being the end high I like so that can contribute to lockout somewhat as well.

Pete talks about the last few weeks as being the major period for putting on bulk (AND resin) and that the process "takes as long as it takes." If you've done alot of damage to the plants they may indeed have quite a ways until finish......regardless of "what the book says."

I would cut your nutes to about 600 Pro Bloom, 200 CalMag and 200 Lk. Pete is absolutely right about this as well.... your job as the grower is to do two things......keep that number down to 1000 whether it be adding water or doing res changes and keep the ph between 5.6-6.2. You need to check and adjust your numbers as often as necessary to keep those parameters. Period.

Photos of the plants and roots would be a huge help to gauge the amount of damage done by overnuting.

 

[Weedhound]

To flush your plants of the serious salt buildup I'd get some FloraKleen and do a 24 hour flush. You can go to straight water but the process will be very slow compared to something like FloraKleen or Clearex and from your post it sounds as though you need to get back on the right track as quickly as possible.

 

[King Tubby]

You should get a lot of bud growth in these next few weeks. This is when plants pack it on, almost dramatically so in some cases. Make sure to let them go as long as they need to finish. Never mind what the package says.....50 days is a little over halfway for alot of strains, but you do have a good strong light and NFT, so that time should come down. Make sure to harvest when the trichs are about 20% amber, give or take depending on preference. Only pick the buds that are ripe, leave others to continue swelling and ripening. This ensures you get maximum yield from your plants.\

Dude, The MAT is *toast*. Funny as being indica-dom I figure it would take to more nutes. The Power Plant seems to be doing better: lower bud sites are still super under-developed.

I've been flushing with plain jane tap water, and no crap, the water jumps to like 1000 ppm when I check it during daytime. I've been swapping it out daily for two days now.

I know that weed is resiliant and all, but I should leave them to finish up? All amber hairs (I know this isn't a sign) and trichs are clear/cloudy under the scope.

Flush for 2 days longer and remove the dead growth and bump the nutes up to a nice 800 or so? Pissed cause these are monsters: vegged for three months!

Last time I run three strains for a first timer in NFT! The haze is looking sweet though. Take the good with the bad: new seeds today and I'm thinking of running just PP/MAT when the haze wraps up.

You guys rule: all of my horticulture buddies are in another state

 

[HeadyPete]

Should have mentioned this first thing....it is not recommended that you mix strains in a single hydro system. Each strain has different requirements and you cannot meet them all with one common batch of nutes. 1 system = 1 strain.

Let them finish, go easy on the nutes, it would be best to see some pix of the condition of the plants before recommending a nute dose. Be patient and harvest by trichome.

Cut only the ripe buds, usually upper, and the lower buds will expand and ripen when they are getting more light.

Look into LST to maximise your buds in your space.

 

[MynameStitch]

If your pH drops lower then your plants are removing more water than nutrients, thus you are burning them and will have to lower the pH.

When they put on there heavy weight and bulk up you know the time to harvest is near and you flush, the plant uses it's stored nutrients to help the bud growth and when the plant has little nutrients the buds won't grow as much, if any....

Petey and weedhound are also correct in there advice, would take theres any day of the week!