You're doing great dude. Keep with it.
I grow in coco, and feeding is tricky until the roots spread out to fill the container. I use as little as 0.5gal pots as my final container... but I think that's about as small as I ever plan on going. I'm settling in on 0.75gal pots.
One thing I'd recommend is to get some cheap starter pots. I use ones that look like this:
They're only about 10 cents a pop. I don't give them feeds until the top turns light brown. Don't let anyone tell you that it's impossible to overwater in coco. That's a lie from the devil! Your plants might suffer through it, but they'll be happier if they get wet/dry cycles (for coco, never completely dry though).
Then, when they grow out in those little pots to the point where you have to feed them twice a day (usually 2-3 nodes), you can pop those suckers into bigger pots... and you're back to feeding every few days as needed.
The problem with bigger pots at that stage is that you're essentially waiting for evaporation to dry your medium. One thing to keep in mind is that roots develop and spread out in search of water. If your medium never dries out, or takes forever to dry out, it actually inhibits growth (among a whole host of other problems). That's why I like the smaller pots initially. You want your medium to dry out because the plant is taking in all of the water and nutrients through the roots and sucking it out of the coco -- not because water is evaporating from the coco. When you achieve a higher frequency of feeding the plant in order to keep the medium wet, you begin to use coco efficiently and realize its benefits.