A while back I created a post on this found below (it's still a good read just to see how much you can save, and to relate to the below).
https://www.rollitup.org/t/uk-alternitave-to-expensive-nutrients.942911/
I've used those same nutrients for a few year now and while they or me are not perfect they do a very good job, I've also learned a bit more since then so hopefully this is a helpful update.
What I came to appreciate is that cana has a wide ppm tolerance range (nutrient strength). In basic terms this means that one person could be using a certain nutrient at full strength, another person could be using the same nutrient at 3/4 strength yet they both get the exact same end good result. The only real difference here is that one person is needlessly wasting nutrients for no extra gain.
This is something worth thinking about, since a lot of liquid bottle company's deliberately tell you to use strengths that are in the upper limit. While it does not ''hurt'' the plant if done right, it means you use more/waste more and thus have to buy more. They also split nutrients up into many bottles when it is simply not necessary.. in practice it essentially creates problems on top of costing you a hell of a lot more.
http://www.angelfire.com/cantina/fourtwenty/articles/profiles.htm
The link above is one the only cana specific ''elemental ppm'' charts I've been able to find that goes into more detail. Elemental ppm is not the same as tds ppm, this was a confusing path to go down but it is an important thing to note. Completely forget about tds meters if you move on to ''powder'' nutrients. What you are dealing with now is elemental ppm that you can work out mathematically for far greater accuracy, you don't need to ''measure'' ppm because you actually already know it before you put it in. I've mostly done the leg work on that so all you really need to do is follow along if you don't have the desire to learn all this, more than understandable ;p.
I have used the above link as the frame work to tailor my own ratios and strengths and so far the below is what I have revised to with no ill effect on health or end weight.
Solufeed base - 0.5 prams per liter (gl for short)
N - 75 ppm
P - 15
K - 132
M - 10
Cal nitrate - 0.5gl
N - 75
C - 95
Epsom salts - 0.5gl
Mg - 50
Su - 65
Mpk - 0.10/0.20/0.30 gpl. >>>Use this stuff cautiously and always double check you worked it out with the decimal fraction and not a whole number. For example 1.0gpl is 9x more P than you need (defo not good for the plant) but not a difficult mistake to make if you get careless. Don't let this put you off, just stay respectful of how concentrated this stuff is and double check you used 0.X decimal.
P - 23/45/69
K - 28/57/84
Total: PPM
N - 150
P - 38/60/84
K - 160/189/216
C - 95
M - 60
S - 65
You'll notice the total PPM of p and K has varying amounts. This is because the ''mpk'' product is used as a slight boost. The more of that you use, the greater the over all P and K will be.
For veg you'd use the values above, but you would use the mpk product at 0.10gpl. This is to bring the P above 30ppm during veg (the minimum amount).
For the stretch in flower nothing really changes. By the end of week 2 going into week 3 you can up the mpk to 0.20gpl (60ppm P). By week 4 to 5 you should be up to 0.30gpl of the mpk boost (84ppm P). At week 7 of a 8 to 9 week strain you can cut the over all nutrient strength to 3/4 and feed that (with run off) until harvest. You can experiment going lower if you like but I would not drop to less than half over all strength. A calculator is a must for this, as is a digital scale to weight out amounts.
If you look over the total ppm amounts they are always within or close to the limits set out by the link frame work. It isn't a perfect match ofc, but close enough where I've seen no ill effect and saved even more on nutrients.
Some things to take into account are your water quality. Mine comes with a bit of calcium, say 30 to 50ppm worth. If you are within that range you should be fine. If you are above that range, say 50 to 100, you should also still be ok, since cana can tolerate high levels of C. If above that, you may need to look into alternative water or calcium source.
The magnesium level has never given me any issues. Some people say they need to use more with leds but I've never had that issue myself (using cobs). I have a sneaky suspicion that the reason some people have mag issues is because their root zone temps are getting too low on account of no longer using hps. This would then lead to slower uptake and mag issues. It is worth checking your root level temps and ensuring they are never any lower than 65F (I try to keep mine at 70F). This will ensure the root zone is warm, happy and taking up what it needs. If your root temps are always in range and you have mag issues, then simply up the epsom salts by 0.10gpl per week until the problem stops, then you know your level.
The N levels seem low for veg, this ''may'' be too low for some strains but again, if you find the leaves are way too light, you can look to up the cal nitrate a little. Since they do have a wide calcium tolerance you can get away with using cnite to up the N. Again, unless you have very hard water.
A tip for the interested. At max the over all ppm is 700 (not including what's already in your water). At such a low ppm you can get away with less run off. I tend to only have around 5 to 10% as an example, this also means you're saving yet again as you use less water/nutrients as run off waste. Saving up to 15% run off reduces the amount of fill ups you have to do. For me that means I save around a full day of my life per year not filling up. I wasted last years free day on working that out ;p.
Lastly. You don't HAVE to use the products I've pointed out, but with a bit more understanding on the various ppm levels it will enable you to tailor your own powder feeds and save a small fortune. You can simply use the PPM values I've given here as a reference point.
