Just an fyi, good quality bagged coco will start with an ec of around .8-1, just from the calcium nitrate it was buffered with. If you just leave that as it is, it can potentially burn seedlings all by itself. The ec of brick coco is all over the place, whatever you do, be sure you prepare it correctly, and consider getting canna to start. I suspect 6 tablespoons of fertilizer will murder your seedlings. I hate to tear down an idea and not give an alternative, so might I suggest using maxigro/bloom (or just maxibloom all by itself) instead? If you use brick, rinse that sucker out like crazy and then soak it in calmag per instructions you can find in these forums or elsewhere, mix in 30% perlite and then double check the EC. Keep your EC below .6 to start, you can water with light nutrients from the beginning, but they can stay at .6 to .8 for a long time unless you see deficiencies. If you do see deficiencies, try upping the EC a little more. To change the EC of your starting media, pour nutrients with your target PH and PPMs through it until the runoff matches. With Maxi I feed once per day once the seedlings have well established roots, feed to a lot of runoff if you are a new grower, always PH to 5.8 and check your ppms. Runoff prevents a lot of problems. By the end of veg you will probably only need an ec of 1 and can go up to 1.4 by around the end of stretch. By the end of veg, when your roots have filled out your final container, begin feeding twice per day at ec of 1. You see people using crazy high ec's, but they aren't needed, in fact they can be counterproductive. It's better to feed a relatively low ec in coco, multiple times per day than give it a high ec. If you are using coco for the first time, I promise you will have better luck with Maxi than with dry nutes due to the CEC (cation exchange capacity) of the media-https://www.icmag.com/forum/marijuana-growing/growing-in-coco-coir/308425-the-chemistry-behind-coco-coir-a-strange-journey-from-ferts-bottle-to-to-buds?t=307683
and if you want to read a few hundred pages about maxibloom-https://www.icmag.com/forum/marijuana-growing/nutrients-and-fertilizers/189616-the-k-i-s-s-method?t=191645 Trust the decade of knowledge accumulated in this post over some youtuber's side hustle.
Good luck!
