Coco grow has been AWESOME for me. First time using it, fairly new to growing in general. Way easier to be successful with it than dirt and the plants do grow way faster. It's also so hard to overwater it's silly and it's not dirt so no bugs.
I don't know about using something made for coco specifically but you do want a complete nutrient set for hydroponic growing. Coco has no nutrient value so while it looks like dirt and walks like dirt and feels like dirt it's still hydroponics and you need to attend to the nutes as such. I use Botanicare Pure Blend Pro-Grow + Cal-Mag and add General Hydroponics Flora Bloom for flowering. With a little seltzer water for leaf feeding. I barely ever have to adjust my water PH if I use the nute strength on the bottle. When I richen the mix during flower cycle I have to bring the pH up a tad usually. Figure you'll need a quart of each for each 2-4 plants per grow including veg. That's what mine eat. I can water every day but usually do it every other day to keep the moisture levels reasonable.
I mixed coco + perlite (quite a bit of perlite... about 30% ) and laid that over a bed of 1 inch gravel in the bottom of a 18 gallon roughneck bin. So far I'm amazed every day at how fast those buggers grow. Make sure you get nutrients with micro's in them... (copper, boron, manganese, magnesium, calcium, etc...) and not just NPK. I like the nute set I use for that. It's pretty complete and so far with it I've had no burning even with fairly rich mixes.
EDIT:
As far as when to water, I use my moisture meter. When it shows up in the 1.9-2.5 range (it's a 0-4 scale (dessicated, dryish, moist, wet) I water. I can actually see the color change in the coco...it stops looking wet at the top. When I see half the top of the coco looking dry I do a meter check and then water it if the check shows it needs it. Usually every 3-5 days for my vegging plants and every 1-2 days for the flowering plants.