Hi James,

Don't get me wrong here, but do yourself a favor and don't go down the road of comparing different manufacturers recommendations, recipes an different formulas, mixes of different products with additives etc. Without "local knowledge", you'll just get lost in comparison of apples with oranges.

As for comparing both products, simply take the 8% nitrogen (of 8-15-36) versus 3% nitrogen of your product. You simply need 2.666 times more of your product to get the same concentration in nitrogen as with 8-15-36. Plus one table spoon of calcium nitrate per gallon also provides some other 80-85 ppm of nitrogen (equals N=8). So, in this example, only considering nitrogen content - With YOUR product you need roughly 5 times more to get the same concentration (in N only).

I've looked up the site of Botanicare and found this product description:

"PURE BLEND Pro is a hydro-organic vegetative and fruit and flower formula which is a specialty custom blend of natural and organic sources of essential major, secondary, and trace minerals in 100% soluble form from the land and sea. "

The actual problem with MOST so called "organic" products seems that they struggle a lot with the raw materials they are allowed to use, respectively with those who can be considered as "organic". Even if many of the ingredients used are mineral components and actually inorganic.

I have been interested in this topic (of organic nutrients) and doing some research over the time. But haven't found any product yet, that transparently delivers all nutrients that are required for a type of vegetables or another. And I haven't understood either why such products actually use unconventional formulas that rime with nothing I've learned about plant nutrition and real requirements. It really seems that their main concern is keeping their stuff clean and "organic", (which is understandable) but completely loose it over the actual nutrient content. Look, 1% of calcium and .5% magnesium is simply a JOKE! In regular hydroponic formulas, calcium is often nearly as high as nitrogen content (in some cases even higher). And magnesium (with actual 40-50 ppm) mostly equals the actual phosphorus content in most formulas. Same for sulfur, which can easily be needed in amounts as high as 5 to 9% - is often not even mentioned.

By the way, I don't exactly agree with what was said about calcium requirements for feafy vegetables or lettuce earlier. Most vegetative formulas have rather high calcium content, although this is due to the fact that calcium is then provided by calcium nitrate, which comes with a high calcium content vs. nitrogen. Hence, some of the calcium content, may in fact be related to this "side effect".

PS: I've even been emailing some manufacturers and challenging them with a few "annoying" questions about the composition of their really unconventional formulas. And if it wasn't strange enough what they sometimes brew, they can't even explain the "why and what for" of the composition. They simply tell by default that their product is the result of years of research and that it has been proven successful (even by a multitude of testers). You bet! They'll not say; sorry that is as close as we can get with hands and feet bind by product restrictions. We know that those limitations and restrictions are partially paradox and incomprehensible. We actually don't agree with most of it - but what the hell can we do!?

Anyway: especially for growing lettuce, I'd recommend a very different approach and product. I'd just using a professional (but conventional) product that uses a CLASSICAL lettuce formula. If you really want to go for "organic", - use it as it comes and as recommended. You wouldn't add anything "chemical" like magnesium sulphate or calcium nitrate, to totally spoil your pure organic product, would you?! Just kidding...

Hint: what ever product you use, always and strictly stick to the manufacturers recommendations- if it doesn't work out, you can and should call them or even blame them. If you are considering some "internet recipe", instead - it's your own fault and mistake if you screw it all up!