what type of nutrients to use coco or soil?

*100% chelated -- essentially means it's already broken down into bit-sized bits can enter the roots without additional efforts and the plant can use immediately. spelled wrong in original answer as "chealted" lol my bad.

you can always use either.. in this case since it's a soilless medium with little to no charge (promix has a light 1EC charge) you'd be better off with a soilless/hydro nutrient setup. "coco" nutes is just soilless nutes. coco is not special. it's not different in any way beside water capacity and the potential to kill your plants if not properly buffered, lol. It's a perfectly fine medium as long as it is prepared well by the manufacturer. Same with promix, but not as extreme.. the concern there is properly pH buffered, which they do. you aslo want a bit more perlite than what the HP bag provides. That is about 20-25% perlite, and you want closer to 50%. The coco portion needs less because it holds less water per volume. 2:1 ratio of coco to perlite for that proportion of mix would be best. So, add perlite, use a soiless/hydro nutrient set of products -- 100% soluble, 100% chealted, 100% plant-ready when dissolved. Feed at 1.3-1.5EC well-balanced diet every irrigation with 10% or more runoff. Simple as that. if coco "absorbs" Ca, that's the exact problem i speak of above.. if that is occuring never buy that brand's coco ever again because they fucked it up and can't be trusted to do a basic thing. unprocessed coco has a tone of Na+ and K+ in the cation exchange sites (CES). It needs to find an equilibrium with the typical ratio of cations that exist in a typical nutrient formula. So, the manufactuer has to soak it in with somethign like calcium nitrate to get those CES sites at a proper equilibrium so that your nutes are not forced out of balance by what is released from the CES sites. Ca++ has a stronger affinity so it easily supplants existig cations.. if not buffered in proper ratio, you then get less Ca, more Na and more K .. this should not happen with any reputable coco product. That is the gist of the chemistry.. not some anecdotal misinformation. therefore you don't need "special" coco nutse.. you simply need the same shit everyone else uses for soilles/hydro context.. because that's all it is. yet another soilless option. it's netiehr better or worse within in the scale of home use as long as it's properly washed and buffered. i've been using 70/30 pre-packaged stuff from mother earth for the last 2 years. every once in a while i have some slightly sick young plants.. most likely due to bad batches of their coco. After 2 years of choosing convenience, i'm going back to Promix (hp, bx, doesn't matter, i get the cheapest one at moment) and add the appropriate amount of perlite to get it to 50/50. coco is fine, but the risk isn't worth it when other equivalent options exist. i don't like having to mix up large batches of this shit.. the convenience of the ready-to-use 70/30 coco products is tough to pass up, but after a couple warning signs (sickly plants) i've been scared back to just mixing up some promix and perlite. lol. getting all over-sophisticated about the substrate does more for your psyche than the plant itself.. as long as it's fluffy and has a good 50/50 air/water mixture in its volume, it's going to work well. it's going to promote good roots.. doesn't matter if peat or coco.. though you need differeing amounts of perlite because each holds different amounts of water per volume. mixing 20 things together will make you feel like you did something special, but zero to no effect. keep it simple.

Your best bet would be going with a nutrient mix that is geared towards coco. Be mindful that coco absorbs a great deal of Calcium and Magnesium. You can “charge” the coco by rinsing it with a heavy dose of CalMag to offset the absorption. Coco specific mixes are best to use in coco obviously. The times I’ve used coco I mixed in an additional 25% perlite so give it better aeration. Hope this helps.

Both coco coir and Promix are soilless mediums they will need full fortification of nutrients Macros and Micros. Coir as the added benefit of being PH stable but the downside it needs a bit more Ca and Mg to off set the cation exchange sites. Promix has the added benefit of holding more water then coir but a downside of going a bit acidic when it decomposes. I've mixed coir and peat moss before. its not bad. It almost always needs a bit more perlite then they have in the package. Aim for 20-40% and always get runoff to prevent mineral buildup in the pots. use w/e nutrient lineup is cheapest and gives a full profile of nutrients at the best concentration/ratios.

either or I wouldnt advise mixing the two but it is possible I have done it. if your going with coco nutrients you would haveto use less and if using soil nutrients you would probably be alright because coco is inert and has no nutrition. though soil does contain things though its over complicating things in my opinion just go with soil or coco lol