Agreed completely. Not ideal for use in hydro that is certain. Urea is organic (in its most pure sense re organic chemistry) and first needs to be broken down into into inorganic NH4 before becoming plant available.
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The myth, of the high P myth?
- Thread starter epicseeds
- Start date
Agreed completely. Not ideal for use in hydro that is certain. Urea is organic (in its most pure sense re organic chemistry) and first needs to be broken down into into inorganic NH4 before becoming plant available.
Really? That's quite amazing. You managed to run off and lab test a coco substrate and do an entire grow using the formula I posted and Spurr's mix in side-by-side trials and then get tissue analysis done all in a single day. Point being - how would you know when you haven't run any form of qualitative test? But seriously, I do have a couple of thoughts and that is firstly I suspect P can come down even further and what is also notable is that all the coco substrate nutrients need to be tested for on a batch by batch basis to look at existing P and K levels being supplied at various points during the crop cycle (only then can you truly equate plant available P and K etc). What is certain, and coming back to the original point is you guys have done some great work here and reps to Yosemite Sam. Sorry Storm Shadow but I haven't looked at Spurr's formula - can you post it up?
paperchaser825
Active member
Thanks paperchaser.
paperchaser825
Active member
Works just fine in RDWC I think they were made for RDWC
Thanks again paperchaser
They look pretty decent - Ca perhaps a bit low but then that would depend on the K in the substrate and its CEC properties. As far as I can tell he is running P at 87ppm in full bloom (may have this wrong) which simply isn't required - 60ppm does her just fine which didn't surprise me given other similar dicots have ideals between 40-75ppm dependent on research and crop type. I.e. Cucumber tends to have higher P requirements than tomato - the latter being expressed as optimum at 40 - 50ppm in mid to late bloom. I guess another influencing factor that needs to be considered is genetics so for instance I'd increase N and drop K for sativa or mostly sativa but run aggressive K as I have for mostly indica strains. My experience is that there is no one size fits all nutrient when discussing numerous sets of genetics from the same genus.Great work all round - definitely one of the better threads I've ever encountered.
BasementBreeder
Member
Will you elaborate on this?
http://www.google.com.au/url?sa=t&r...2wSA3ws-dnzZGB8qh8yLzgA&bvm=bv.73231344,d.dGc
Hopefully that link works for you but google it and you'd have the answer. Typically 1EC = 550ppm is the number expressed in scientific literature. Keep in mind that all ppm meters first measure in EC and then run a conversion program to ppm - so there is no one standard. So U.S. standard is 500ppm = 1EC while European standard is 640ppm while e.g. Australian standard is 700ppm. Quite bloody laughable really when most/much literature expresses it at approximately 550ppm. To read more - here's something I have written on it http://www.manicbotanix.com/hydroponic-grow-guide/ec-to-ppm-conversion-chart.html
Hope that helps
Nope I definitely do not have anything to do with MB Nutes.
Thanks Diggaz I'm glad it helped. I'll keep adding more info over time and I am seriously considering turning it into an online mag written by growers for growers (rather than the hydro industry for growers). Just contemplating this now but involved in another massive project which has tied up my time.
paperchaser825
Active member
Anyone know where Ionic Bloom fits into all this? Is the P too high? Is the K ok? Is the N too much? Discuss.
paperchaser I'm just writing about all this now but if you go to http://www.manicbotanix.com/calculators/ppm-in-solution-calc.php
and grab the guaranteed analysis from the label and enter in how many ml/L you are using and then all the %w/v values on the nutrient label the calculator will tell you the ppm in solution. Remember to convert P205 to P and K2O to K. There is a calculator on the same page that does this for you. Keep in mind mate that there are tolerance levels so for instance 60ppm is perhaps as low as you want to go before slipping towards a P deficiency while way too much P will lock out microelements - its not just so simple as to say 60ppm is optimum (i.e. if say you had 80ppm in solution this likely wouldn't be a problem at all but nothing growth wise would be gained). The research here was really more to establish what ran to perfection and how low P could go. To be honest I was very surprised it was as low as 60ppm and perhaps even lower so cred to Sam for his research.
paperchaser825
Active member
I did the calculator, but on a different site. I couldn't figure out the SG because I'm kinda dumb and really high. Anyways....
When I adjusted the feed rate on the calculator I used to make the total Nitrogen equal the K was also right on, but the P was @ 40. My only question at this point is where the fuck do I get Boric and Fulvic acid? I found the humic acid, which I read recently somewhere around here is essential to RDWC. Also, my General Organics CalMg is apparently different from the botanicare brand by a good 2 percent in Mg. 5/1 Ca/Mg in the General Organics brand. 5/3 in the botanicare. I'm wondering if I can just use it at 5ml/gal and then supplement my Mg with the epsom without overfeeding sulfur. Lemme know if you guys have any help for me.
When I adjusted the feed rate on the calculator I used to make the total Nitrogen equal the K was also right on, but the P was @ 40. My only question at this point is where the fuck do I get Boric and Fulvic acid? I found the humic acid, which I read recently somewhere around here is essential to RDWC. Also, my General Organics CalMg is apparently different from the botanicare brand by a good 2 percent in Mg. 5/1 Ca/Mg in the General Organics brand. 5/3 in the botanicare. I'm wondering if I can just use it at 5ml/gal and then supplement my Mg with the epsom without overfeeding sulfur. Lemme know if you guys have any help for me.
paperchaser825
Active member
Solubor is the finest B supplment you'll find. I use it myself at a constant feed of .5ppm.
