Sooo do you PH water with Pro Mix or not?

I never flushed once I always watered to 15-20% runoff or so.

This is just my personal opinion... Dyna-Gro makes a great veg fert. Their other formulas are not the best, too much P.
If I was gonna run DG the whole way. I would switch to their 7-9-5 formula for flower and maybe up the K2SiO3 a bit for the potassium.

There is a vid out there where Dr. Bugbee really pushes the use of Silica for cannabis, especial during trichome development.

7CardBud said:

I never flushed once I always watered to 15-20% runoff or so.

This is just my personal opinion... Dyna-Gro makes a great veg fert. Their other formulas are not the best, too much P.
If I was gonna run DG the whole way. I would switch to their 7-9-5 formula for flower and maybe up the K2SiO3 a bit for the potassium.

There is a vid out there where Dr. Bugbee really pushes the use of Silica for cannabis, especial during trichome development.

Click to expand...

Interesting note on the silica. I use a bit of protekt in veg currently for silica so nice to know I can continue into flower.

Turns out 1/2 tsp of FP per gallon is way too hot, even in Promix in veg. I plan to flush a gallon of distilled water PHed to 6 to help the salt build up. They definitely have a crusting on top when I scratch up the surface soil. Should I then add the normal feed at 1/4 strength after or at this point give them time to finish off what's still present after flushing? The plant that is by far the healthiest is showing some N toxicity. This other poor bastard just can't catch a break. That root ball crumbling during transplant has really set this gal back a few grades already. So to feed after flushing or no?

RuggedWombat said:

Turns out 1/2 tsp of FP per gallon is way too hot, even in Promix in veg. I plan to flush a gallon of distilled water PHed to 6 to help the salt build up. They definitely have a crusting on top when I scratch up the surface soil. Should I then add the normal feed at 1/4 strength after or at this point give them time to finish off what's still present after flushing? The plant that is by far the healthiest is showing some N toxicity. This other poor bastard just can't catch a break. That root ball crumbling during transplant has really set this gal back a few grades already. So to feed after flushing or no?

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7g containers & 1 gallon of water make not a flush. It takes me nearly 2g to get any runoff in 5g bags.

Also...why the guess work? Super easy to get a read on EC/PPM before you feed your plants.

LeastExpectedGrower said:

7g containers & 1 gallon of water make not a flush. It takes me nearly 2g to get any runoff in 5g bags.

Also...why the guess work? Super easy to get a read on EC/PPM before you feed your plants.

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Sorry flush wasn't the best term. I believe giving them a simple water feeding with a bit of runoff will probably give them the relief they need. 2 gallons was just enough to get a couple of ounces of runoff. What do you mean by guess work though? I do measure the ppm and ph on everything I put in the plants. My only guess work was on how strong the feed would need to be since I'm not doing soil now so there aren't any nutrients already there. Ive ran 1/4 strength FP numerous times with pretty good results overall. FP has always been very strong, especially N.

RuggedWombat said:

Sorry flush wasn't the best term. I believe giving them a simple water feeding with a bit of runoff will probably give them the relief they need. 2 gallons was just enough to get a couple of ounces of runoff. What do you mean by guess work though? I do measure the ppm and ph on everything I put in the plants. My only guess work was on how strong the feed would need to be since I'm not doing soil now so there aren't any nutrients already there. Ive ran 1/4 strength FP numerous times with pretty good results overall. FP has always been very strong, especially N.

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If you're looking to remove salts from your medium, I'd be looking for a liter or more of run off. In my weekly feed/water schedule, I generally already get 1.5 liters per bag of runoff with 2g going in the pot. If I'm looking to really knock down what's in the medium I go up to pouring in 3 or 4g per bag. A few ounces of runoff may as well be none.

Using powdered nutrients I feed by measuring. Generally bumping up or down by only half a gram or a gram at a time. I'm also taking readings for EC...some plants do want more or less...but if you were feeding 1/4 a teaspoon and you doubled that...that's not an incremental increase that is twice as much, which isn't much precision in your titration.

LeastExpectedGrower said:

If you're looking to remove salts from your medium, I'd be looking for a liter or more of run off. In my weekly feed/water schedule, I generally already get 1.5 liters per bag of runoff with 2g going in the pot. If I'm looking to really knock down what's in the medium I go up to pouring in 3 or 4g per bag. A few ounces of runoff may as well be none.

Using powdered nutrients I feed by measuring. Generally bumping up or down by only half a gram or a gram at a time. I'm also taking readings for EC...some plants do want more or less...but if you were feeding 1/4 a teaspoon and you doubled that...that's not an incremental increase that is twice as much, which isn't much precision in your titration.

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They have had a total of 5 gallons of water PHed down to 5.9. The runoff is probably 2 gallons which I'm okay with given the 4 feedings at probably what was 2x what they needed. They already look better. The runoff is pretty nasty unless the color is coming from something in the Promix. Once they fully dry out I'll be doing 1/4 tsp per gallon. Yes I need to switch to ml lol I even have the syringes down to 1ml I'm just stubborn. I'll have some updated pics probably tomorrow once they have some time to dry.

That runoff looks about right. It leeches some of the particulate matter out of the peat, so brown is what you get.

The plants are looking much better! The medium still isn't dry however so best to let them take their time. I'll be feeding about 1/4 tsp of both protekt and FP when they finally dry out. That will also give them even more time to eat some of what might be left. I have a feeling going forward 1/4 tsp is more then enough enough to get through all of veg and maybe even the flower stretch. I guess we shall see once they continue to balance out. Also plant #2 and 3 have some incredibly thick stems already! Gotta love protekt.

LeastExpectedGrower said:

That runoff looks about right. It leeches some of the particulate matter out of the peat, so brown is what you get.

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They finally dried out today and I can't tell if they look better or worse. I did a quarter strength from what the feeding chart suggests, and yet my gut tells me there are still way too many nutrients remaining. Or are the pots too oversized for the root system? They look over watered but I didn't even get runoff. I've noticed some compaction as well already which maybe in hindsight I should have chosen HP instead of BX. Too late to make some of these corrections for this grow, but I can't find the right balance between nutrients and watering. I used to do water feed water feed and using nutrients every watering feels like I'm drowning them. Also note interveinal chlorosis and the twisted growth.

chuckeye said:

FWIW > I use ProMix HP in 3 gallon fabric pots with Mega Crop one part.

I feed with every watering right up to harvest.

After the fourth or fifth week I water to just a bit of run off, 1 gallon.

During the most vigorous growth it's every two days.

I'm nearing the end of flower in my current grow and I'm getting almost three days before watering...

I judge when to water by lifting the pots. My goal is light, not quite bone dry but close.

Well water with a ppm of 450-500 depending on the season and ph of 7.5

No PH down !

This is day 97, 47 of flower...

View attachment 5219668

Current grow journal

Cheers

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I've done pretty much the same thing this grow of 2 Autoflowers. 2 year old bag of Promix HP unamended, 3G fabric pots, and Megacrop 1 part that I tested on my garden veggies this year. Tap water with 7.8 PH and I've had to feed them every day or 2. Depending on time of cycle. Every feed I let a bit drain to waste. I see no major issues.

I think you all ready figured it out. You started in way too much media and you used the higher water retention BX mix. I bet a good amount of the water is evaporating through the grow bag before the plant uses it and is leaving all the salts.

I'm running FP right now to veg a few plants. They are in quart sized plastic pots and are little smaller than your smallest plant.
Feed is 4tsp of FP in 5 gallons. Plants are watered daily to a good 20% runoff.

If you run much smaller pots you will have more dry cycles and may avoid the soggy plant look. It also gives you more cycles to flush the media. My runoff was almost clear by the end of the first week.

7CardBud said:

I think you all ready figured it out. You started in way too much media and you used the higher water retention BX mix. I bet a good amount of the water is evaporating through the grow bag before the plant uses it and is leaving all the salts.

I'm running FP right now to veg a few plants. They are in quart sized plastic pots and are little smaller than your smallest plant.
Feed is 4tsp of FP in 5 gallons. Plants are watered daily to a good 20% runoff.

If you run much smaller pots you will have more dry cycles and may avoid the soggy plant look. It also gives you more cycles to flush the media. My runoff was almost clear by the end of the first week.

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At this point should I run a few fresh water feedings? I have some 3gallon fabric pots I could downpot as an option as well but no way of knowing how big the roots are now. Just debating what to do at this point as I'm scared to start flowering with them having issues. Overwatering and salt build up are making it impossible to know if they are actually deficient in anything. I'm debating if I should even run fresh water now today even though I watered them last night to try to free up the medium. It definitely doesn't feel near as fluffy when dry as it did new. I may just do fresh water runoff feedings until they start to show some yellowing at the bottom. They look like they have a ton of N look at the deep color. The brown dead spots are most likely from swimming in nutrient soup.

Guess the question is do damage control now and give them fresh water until runoff or wait until they dry and then do fresh water for awhile until the medium frees up and they bounce back? They look better than they did but the tallest is already 23 inches tall so I need to get these in shape for flowering.

I always pH every input into soil. Cannabis is a plant that will grow and flower under the worst of conditions. Optimal conditions concerning environment, soil and inputs equates to higher quality end product.

It only takes a second to adjust pH and the results are completely worth it if you are trying to achieve the best cannabis possible. If you just want to grow something good enough, have at it. This is for people who strive to have the best.

For promix I like to adjust the watering solution to the 6.3-6.5 range.

As far as letting the promix completely dry out, don't do it. Promix is peat based and once peat drys it is very difficult to get it wet again. Also completely drying affects the microbes in a negative manner. There are benefits to letting the soil become dryer before watering for sure but avoid completely drying as in super light containers.

Also fertilizing bone dry soil is not a good idea. If the soil gets that dry it is best to rehydrate with plain pH'd water then add nutrients.

To the OP, you plants are suffering from the soil being too dry most of the time.

Modern Selections said:

I always pH every input into soil. Cannabis is a plant that will grow and flower under the worst of conditions. Optimal conditions concerning environment, soil and inputs equates to higher quality end product.

It only takes a second to adjust pH and the results are completely worth it if you are trying to achieve the best cannabis possible. If you just want to grow something good enough, have at it. This is for people who strive to have the best.

For promix I like to adjust the watering solution to the 6.3-6.5 range.

As far as letting the promix completely dry out, don't do it. Promix is peat based and once peat drys it is very difficult to get it wet again. Also completely drying affects the microbes in a negative manner. There are benefits to letting the soil become dryer before watering for sure but avoid completely drying as in super light containers.

Also fertilizing bone dry soil is not a good idea. If the soil gets that dry it is best to rehydrate with plain pH'd water then add nutrients.

To the OP, you plants are suffering from the soil being too dry most of the time.

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So since I just fed nutrients last night with dry soil, should I give them plain water until runoff today to free up some of the nutrients? A lot of it looks like overwatering which I know is more from the pot being too big, but I already have ideas on what not to do going forward. I'm just trying to figure out how to get them back on track to start flowering as I have no idea how many nutrients might be left in the medium. They already have poor drainage I'd hate to be potentially watering them even more. I guess I'm trying to figure out right now what should I be giving them and how often. It sounds like don't let them dry out a lot but I'm still left with trying to figure out if they have way too many nutrients. Surely it's almost always too much versus not enough when it comes to nutrients? Here they are just now and I watered them yesterday afternoon. I always PH to 5.8-6 before putting anything in them as well. The other pic is after watering yesterday; looks like overwatering to me. Next time I'll run like 1gallon fabric pots with HP for more drainage and water more frequently. Sadly I have to figure out how to work with what I have right now until then. I also only gave them 1/4 strength from the feed chart but they started with half strength which proved to be way too much. Also the twisted growth and crispy brown spots are making me lean toward running fresh water for awhile but I get scared with it being Promix and not knowing how long nutrients left in the medium will sustain the plants. I see people feeding nutrients every day and I'm worried they can barely handle it 2x a week.

It just looks like the pH is too low. I see quite a bit of leaf curl. I don't think you have too much nutrient or water.

When time to water again I would give them a blend of Veg/Bloom nutrient at half strength, pH'd to 6.5 until runoff. I consider runoff 20% of what's given.

What is your light cycle? 18/6 would be best currently. Right before lights out you could give them an epsom foliar at a rate of 1 tsp per gallon and spray the leaves until runoff. Yes, pH the foliar to 6.5

I the low pH is playing havoc on the plants ability to uptake Mg properly.

Modern Selections said:

It just looks like the pH is too low. I see quite a bit of leaf curl. I don't think you have too much nutrient or water.

When time to water again I would give them a blend of Veg/Bloom nutrient at half strength, pH'd to 6.5 until runoff. I consider runoff 20% of what's given.

What is your light cycle? 18/6 would be best currently. Right before lights out you could give them an epsom foliar at a rate of 1 tsp per gallon and spray the leaves until runoff. Yes, pH the foliar to 6.5

I the low pH is playing havoc on the plants ability to uptake Mg properly.

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This is where cannabis vexes me. There are just as many saying the opposite of what you are. Not saying you or them are wrong but it makes it impossible to consistently know what best practices are. I've also read to treat Promix like hydro so PH should be closer to the 5.5- 6 range. You're suggesting a range more in line with soil. Half strength would be twice as much as I just gave them. Aren't the burnt tips and twisted growth indicative of burn? I'm running 18/6 light cycle. I will say I didn't do runoff yesterday as Im worried the root system isn't big enough so I'm trying not to drown them. Flushing with 5 gallons took about a week to dry out, but it seems now that I probably should have watered them a day or two earlier when they were moist, not dry. The overall drooping and leaf serration damage look like overwatering to me which again might be from the pots being too big. I will say the leaves do feel dry and papery so maybe uptake is the issue but I feel like it's moisture stress.

Modern Selections touched on this, you want to water full waterings with runoff when the pot gets very light, but before wilt and the mix is crumbly dry. If you let the media go bone dry you will get hot areas where the media has lost its hygroscopic ability.

It's usually not a good idea to interrupt the wet and dry cycles, just make changes next watering.

Since you don't know where you're at you can douche your way to reset.

I would run 10 gallons through each pot at your next required watering. The 1/4tsp FP a gallon is a pretty mild solution and should be fine to flush.
Also adding a surfactant wouldn't hurt either, it will help break down hot spots if you have them. A few drops of dish soap per gallon or something else suitable.

7CardBud said:

I think you all ready figured it out. You started in way too much media and you used the higher water retention BX mix. I bet a good amount of the water is evaporating through the grow bag before the plant uses it and is leaving all the salts.

I'm running FP right now to veg a few plants. They are in quart sized plastic pots and are little smaller than your smallest plant.
Feed is 4tsp of FP in 5 gallons. Plants are watered daily to a good 20% runoff.

If you run much smaller pots you will have more dry cycles and may avoid the soggy plant look. It also gives you more cycles to flush the media. My runoff was almost clear by the end of the first week.

Click to expand...

Is this coco or Promix? How do they get enough oxygen when watered every day like that in pro mix? Also you're feeding like twice the amounts as me and way more often so I'm really confused if it's too much or not enough that's hurting but it sounds like it isn't the amount of nutrients that's the problem, it's the ability to uptake which is either being hindered by poor wet dry cycles or possibly PH as suggested above.

7CardBud said:

Modern Selections touched on this, you want to water full waterings with runoff when the pot gets very light, but before wilt and the mix is crumbly dry. If you let the media go bone dry you will get hot areas where the media has lost its hygroscopic ability.

It's usually not a good idea to interrupt the wet and dry cycles, just make changes next watering.

Since you don't know where you're at you can douche your way to reset.

I would run 10 gallons through each pot at your next required watering. The 1/4tsp FP a gallon is a pretty mild solution and should be fine to flush.
Also adding a surfactant wouldn't hurt either, it will help break down hot spots if you have them. A few drops of dish soap per gallon or something else suitable.

Click to expand...

As suggested a couple of times now; would better wet dry cycles solve the issues? It sounds like I was never giving them too many nutrients as the most they got was 1/2 tsp FP per gallon which is like half of what some other FP users on here are using. How will I know when they've finally eaten what's left in the medium? Or would you do a full flush and then go at half strength each watering going forward? I just want to make sure after I hit the reset button that they won't wind up right back where they are now. I'd like to see a solid week of improvement before I risk switching to flower.

Treat promix like soil for pH purposes. I know there is just so much parroted bad info on this site, it makes it impossible to determine who to listen too. I have been using promix or the like since the end of the 90's. I'll post some pics of promix plants pH'd 6.3-6.5.

It is not nutrient burn. It is too little nutrient. The green in the veins is the nutrients you gave last entering the plant. Just not enough to fill out the leaf. Those plants are pretty good sized and I would feed them 3/4 strength if they were healthy. Since they are a little under the weather, I would go half strength just to not give them more than they can deal with as they are in reapir mode.