The Lounge : Growers Round Table Discussion Thread

[frankslan]

how are your plants looking

one plant got really started drooping pretty bad, 40 gals was a little much I think, but it is looking better today. I can see the yellowing starting to begin now at day 19 when it usually starts for me. Im going to do that gypsum soon after they dry out.

 

[jackspratt61]

Led is right about gypsum...used correctly it works wonders. Your plants will be wanting P and K asap along with Ca. Do you have any MKP? How many weeks do the plants normally flower?

 

[Mountain Kine]

Nice that's good to know

I bought a microclone starter kit from planttc online. I've been reading about and watching videos on kitchen culture. I will do some experimenting with some of those recipes. I'm not sure what recipes I'll be trying just yet. The kit I bought does not have agar it's a more simplified version. I'll post the ones I try.

It may already be mixed in or another gelling agent was used in its place.

The preparation I am using includes: MS basalt salt mix, 30g sucrose, 8% agar, 2uM MT, plus Gamborg vitamin preparation and 500mg activated carbon.

 

[frankslan]

my plants usually flower 10-11 weeks Last run the buds came out good at least.

whats mkp. gypsum is in the mail...

 

[frankslan]

Mono Potassium Phosphate or MKP, the Ultimate Bloom Booster. no i have sample of pk from root organic.

 

[jackspratt61]

not familiar with the product but your plants will be wanting P and K in equal amounts. The analysis on the label for P should be 2x the K or as close as you have.

I have a similar mix with high undigested Ca,,,I have been feeding them 350-400ppm P and K and still they want more. As you raise the % of Ca these plants increase their need for food...be prepared.

 

[frankslan]

cool thanks i read a lot of this thread i remember seeing your soil test not as bad as mine but similar.

 

[Mountain Kine]

It may already be mixed in or another gelling agent was used in its place.

The preparation I am using includes: MS basalt salt mix, 30g sucrose, 8% agar, 2uM MT, plus Gamborg vitamin preparation and 500mg activated carbon.

.8% not 8

 

[Lightweight]

I have a question down the line here for the chemistry nerds.

So awhile back I switched to doing 5 gallon coco hempy buckets in my greenhouse and for the most part I have been really happy with the switch. I've been mixing my own fertilizer and the quality has been great and it has been cool messing around with different ratios. I've successfully given my plants boron toxicity, manganese toxicity, potassium deficiency, magnesium deficiency and a very slight zinc deficiency (probably from cranking Cu so high) trying to find the limits of different minerals. I'm still currently pushing Cu and Zn up. I haven't had any bug pressure at all lately; literally zero on my flowering plants which is impressive for living in the warm humid tropics where bugs never die off and we've got just about all of the different varieties too and I'm not spraying or doing anything for bugs. I'm still getting some botrytis (not too bad, but some) and I think extra Cu will help. My elemental N-P-K is currently 5-5-5.

I can mix 550 gallons of fertilizer solution at one time, but I've been mixing up 100 gallons at a time to mess with different numbers. One of the really nice things about doing (passive) hydro is how quickly deficiencies or toxicities show up. It's been really helpful for messing around with the ratios especially since on hotter days the plants will soak up at least a couple gallons of water each (big plants for 5 gallons buckets).

I use all the normal stuff for my mix like CaNO3, MgSO4, MKP, sulfate micros, etc, but on my last couple batches I started off by filling up 100 gallons of rain water in one of my tanks and added a couple tablespoons of soluble fulvic acid powder (from CHN) and then put in 18ml of 85% phosphoric acid and then added 88 grams of CaCO3 which resulted in a stable pH of 6 and then I added the rest of my fertilizers. The pH stayed at 6.

So my question for the chemistry nerds is:
Will 85% H3PO4 always form precipitates with CaCO3 even in a diluted mixture? I know it will when it's in a concentrated solution, but what about with the amounts I used in 100 gallons? And if that will theoretically form precipitates is there any calcium form(s) that won't form precipitates with H3PO4 and can raise the pH?

Just FYI, I haven't noticed any precipitates in my tank, but my rain water is a little murky so I'm not sure if I could see precipitates very well if there are some.

P.S. just FYI, the phosphoric acid is to raise the P to be equal with K if that's not obvious, ha ha!

 

[jidoka]

How many ppm of P does that add to your final solution?

The CaCO3 itself has very low solubility so the interaction with P won’t be a problem. Are you using micronized caco3?

In veg I have gone to a 5-1-5 mix with improved results. Just beginning flower testing so I can’t say on that

 

[bsgospel]

I have a question down the line here for the chemistry nerds.

So awhile back I switched to doing 5 gallon coco hempy buckets in my greenhouse and for the most part I have been really happy with the switch. I've been mixing my own fertilizer and the quality has been great and it has been cool messing around with different ratios. I've successfully given my plants boron toxicity, manganese toxicity, potassium deficiency, magnesium deficiency and a very slight zinc deficiency (probably from cranking Cu so high) trying to find the limits of different minerals. I'm still currently pushing Cu and Zn up. I haven't had any bug pressure at all lately; literally zero on my flowering plants which is impressive for living in the warm humid tropics where bugs never die off and we've got just about all of the different varieties too and I'm not spraying or doing anything for bugs. I'm still getting some botrytis (not too bad, but some) and I think extra Cu will help. My elemental N-P-K is currently 5-5-5.

I can mix 550 gallons of fertilizer solution at one time, but I've been mixing up 100 gallons at a time to mess with different numbers. One of the really nice things about doing (passive) hydro is how quickly deficiencies or toxicities show up. It's been really helpful for messing around with the ratios especially since on hotter days the plants will soak up at least a couple gallons of water each (big plants for 5 gallons buckets).

I use all the normal stuff for my mix like CaNO3, MgSO4, MKP, sulfate micros, etc, but on my last couple batches I started off by filling up 100 gallons of rain water in one of my tanks and added a couple tablespoons of soluble fulvic acid powder (from CHN) and then put in 18ml of 85% phosphoric acid and then added 88 grams of CaCO3 which resulted in a stable pH of 6 and then I added the rest of my fertilizers. The pH stayed at 6.

So my question for the chemistry nerds is:
Will 85% H3PO4 always form precipitates with CaCO3 even in a diluted mixture? I know it will when it's in a concentrated solution, but what about with the amounts I used in 100 gallons? And if that will theoretically form precipitates is there any calcium form(s) that won't form precipitates with H3PO4 and can raise the pH?

Just FYI, I haven't noticed any precipitates in my tank, but my rain water is a little murky so I'm not sure if I could see precipitates very well if there are some.

P.S. just FYI, the phosphoric acid is to raise the P to be equal with K if that's not obvious, ha ha!

I think you will be fine. Everything I find on the subject indicates that it's a question of temperature and pressure that could cause precipitation or flocculation. At 20% h3po4, it happens rather quickly but they're applying massive heat to extract hydroxyapatite. You should be getting dicalcium phosphate in the soil if the binding is normal- and in the solution at dilute rates shouldn't fall out.

 

[Lightweight]

How many ppm of P does that add to your final solution?

The CaCO3 itself has very low solubility so the interaction with P won’t be a problem. Are you using micronized caco3?

In veg I have gone to a 5-1-5 mix with improved results. Just beginning flower testing so I can’t say on that

Each ml of H3PO4 adds 119 ppm of P so 18 ml adds 2142 ppm (per 100 gallons for my solution).

I (lucky) guessed on the amount of CaCO3 to use for balancing the pH based on the solubility chart on wikipedia for H3PO4 and CaCO3 (link should be below).

https://en.wikipedia.org/wiki/Calcium_carbonate#Solubility_in_a_strong_or_weak_acid_solution

That chart plus the statement near the bottom of the article that states, "Thus phosphoric acid is more efficient than a monoacid since at the final almost neutral pH, the second dissociated state concentration [HPO2−
4] is not negligible" got me thinking it might be effective for what I'm trying to do.

And I'm not sure if the CaCO3 is micronized, but it is a really fine flour.

I'm using the 5-5-5 for veg and flower. I just use different strengths for different plant stages.

I'll try leaving out the CaCO3 and H3PO4 on the next batch and just use some KOH to bring the pH up.

Thanks for your input Jidoka!

 

[Lightweight]

I think you will be fine. Everything I find on the subject indicates that it's a question of temperature and pressure that could cause precipitation or flocculation. At 20% h3po4, it happens rather quickly but they're applying massive heat to extract hydroxyapatite. You should be getting dicalcium phosphate in the soil if the binding is normal- and in the solution at dilute rates shouldn't fall out.

Thanks for your input bsgospel!

I'll look into it. Do you know how it affects solution pH? And do you know a good online source for the most soluble kind? I'm pretty sure no company on Maui sells it. Product availability is somewhat limited here.

 

[jidoka]

Lw what is your other source of P? Just mkp or do you pekacid?

If you like highish P
3 cano3 and 1.64 mkp is 123-98-123-150.
Once you get past stretch you can bump mkp, no problem. The extra k drives ec. Plus if you have any alkalinity in your water your pH should need to come down

 

[jidoka]

Or, if you wanna raise pH trade some mkp for like 0.3 agsil. Keep that k=n during veg/stretch. Then bump the mkp

 

[Ibechillin]

In veg I have gone to a 5-1-5 mix with improved results. Just beginning flower testing so I can’t say on that

If you like highish P
3 cano3 and 1.64 mkp is 123-98-123-150.
Once you get past stretch you can bump mkp, no problem. The extra k drives ec. Plus if you have any alkalinity in your water your pH should need to come down

Thanks for sharing man, Looking over the tissue analysis results from Advanced Nutrients awhile ago I estimated around 4.5-1-4.5 ratio would work pretty well as a base to make adjustments from. Ive noticed you and slownickel are kind of on opposite sides of the fence when it comes to P application, alot of searching ive done suggest around 40-60ppm P in bloom ideal, not enough with the high calcium?

 

[Lightweight]

Lw what is your other source of P? Just mkp or do you pekacid?

If you like highish P
3 cano3 and 1.64 mkp is 123-98-123-150.
Once you get past stretch you can bump mkp, no problem. The extra k drives ec. Plus if you have any alkalinity in your water your pH should need to come down

I was using Pekacid, but it's just MKP now.

And my rainwater is has a pH of about 7, but it's pretty easily manipulated since there's not much in it.

Or, if you wanna raise pH trade some mkp for like 0.3 agsil. Keep that k=n during veg/stretch. Then bump the mkp

Thanks for the tips Jidoka! I'll give that a try on the next batch

 

[jidoka]

Ibechillin...those an tissue tests are the direct result of bottle nutes. High N and K and low Ca

As far as P you gotta be careful if you are talking soil or hydro. I am talking hydro veg

I am not comfortable saying how low P can go in flower yet.

 

[GSWCali]

I've been enjoying the base Jidoka provided , 123-98-123-150-30 (N-P-K-Ca-Mg). After doing some reading it seems a lot of people are running a moderately low P, around 60 and below. I made a batch of 123-60-123-150-30 by using a little less MKP and getting the rest of K from Potassium Sulfate. My plants seem to enjoy the P at 60 instead of 98, I might lower it some more just to test because I think I was having uptake problems with K with the 98P.

My micros at the moment are Mn3 Fe2 Zn1.2 B 0.6 Cu.45. When it comes to micros, does anyone keep them constant throughout veg and flower or adjust according to what the plant is telling you or just adjust in general? Not too knowledgeable with micros.

 

[Mountain Kine]

If you use Cal Prime Fromm haifa instead of yara cal nit you will get 132 N instead of 123 but 185ppm ca instead of 150.

3-1.2-1.2-.4 cal nit mkp epsom k sulfate has been working really well for me