@Arnis&Weed 
Welcome to AFN
Coco is really a form of hydroponics, this is a primer I wrote on using salts (fertilizer) that applies to all forms of hydro;
The proper use of “salt” based fertilizer to grow Auto Flowering Cannabis.
Salts:
Natural and man made any chemical compound formed from the reaction of an acid with a base, with all or part of the hydrogen of the acid replaced by a metal or other cation. Learning how to use salt based fertilizer properly is being environmentally responsible.
The first thing you need to learn is to get a ladder and put the Cal-Mag on the top shelf out of reach. Put the ladder away. I do not know how it got started but Cal-Mag is the number one abused product in the tent. It alone is...
Then as far as light is concerned get the photone app for your smart phone. Learn about DLI day light integral - Look it up on Google
Keep The Guesswork Out of Grow Lighting: Measure PAR / PPFD for Plants
play.google.com
What you need to learn about watering will come with practice. Here are the basic rules: Never let the soil dry out. Soil and or coco can become hydrophobic if allowed to dry. This means it repels water. This in turn will create dry pockets in the soil and the roots and microbes will die there. If your soil - coco have accidentally dried out use a surfactant to help re-wet it. I like yucca powder. Don't let soil remain soggy by watering too much too often. Root rot, damping off, molds, fungus gnats and other problems start in soggy soil. When you do water
water the entire pot. How to learn when to water starts before you plant the seed. Fill your container with fresh soil/coco and weigh it (heft it) this is the lightest weight and consider it a dry pot. Now slowly water until the soil/coco will no longer absorb the water and run-off begins; weigh the pot (heft it) this is the maximum water, the wettest the pot can get. The difference between wettest and driest is the maximum water weight, for ease of explanation lets just say the water weighs 20 pounds. When the pot loses 10 pounds
(half of the water weight) it is time to water again. Slowly wet
ALL of the soil until run-off begins. There is an art to watering. Make sure there is an air gap under your pot, you do not want runoff to be reabsorbed and if no air then anaerobic microbes can grow. This is a cause of root rot. Coco can be fertigate many times a day if you want to continually present fresh balanced nutrients to the roots. Begin fertigation 2 hours after lights on and end it 2 hours before lights out.
Now for coco. Coco is a form of Hydroponics and you water with nutrients every time you water. It is called fertigation when nutrients are mixed in the water. The idea behind coco is a substrate that you cannot over-water. It simply drains out the bottom pulling air into the roots. This allows you to fertigate several times a day presenting fresh in balance nutrients to the roots all day. Do not fertigate sooner than two hours after lights on or after two hours before lights out. During the night the roots will be exuding substances to feed the microbes so they will produce more nutrients the plant is look for. If you fertigate too soon after the lights come on the plant will not have a chance to take in the nutrients the microbes made before you wash them out. Then at night the plants do not like to go to bed with wet feet . Just because it is hydro does not mean it does not have a rhizosphere it does. Always fertigate to 15% run-off every day in coco. Don't let the pot sit in that drainage remove it to waste (feed your outdoor plants with it).
You should always water the entire pot. If soil, peat or coco are allowed to dry out they can become hydrophobic (repels water). It makes it hard to re-wet the medium. You can end up with the dry pockets you mention. Use a surfactant in your fertigation if this happens to you. I run yucca powder as a basic item in my drip to waste hydro. It is a natural surfactant. Good for foliar feeds also.
A tap root can grow 9 inches in three days and the laterals are not far behind. Roots will not grow into dry soil. This is the mechanism behind air pruning. So if you have a dry pot you will stunt the root growth at the time when it is most crucial. Water/fertigate the entire pot when it is needed.
Coco is hydro and all of the hydro rules apply. Fertigate from day 1. Fertigate means to water with a nutrient solution. When the plant is a seedling you do not need to fertigate every day but you must not let coco dry at all - ever. Any day that you do fertigate you must do so to 20% run-off to waste by the end of the watering period. (My run off goes to the outside yard.) The watering period is from 2 hours after lights on to two hours prior to lights out. The reason you must not let coco dry has to do with the cation exchange and not keeping the seedling moist. Transplanting is ok if you time it correctly but that is not easy to do so it is better to use a starter cube of some sort right in the pot - root riot, rock wool etc. Be careful not to over-water the cubes. They hold more water than the coco will. You may find you need to fertigate the pot and not the starter cube especially if you are using fabric pots. Use a good fertilizer line made especially for coco. Buy the entire line and follow their feeding chart at about 60% strength for auto flowering plants and up to full strength for photo period plants.
Some of that is redundant because I copy and paste from a document I used a lot when I worked in the Infirmary here a few years back.
Good luck
..my hint is...if you confuse our helpers you are probably doing it wrong..
..coz they are really good...
..I probably wouldn't have signed into a cannabis forum if I hadn't killed my first grow..Good Luck..and if you get stuck..jump into Live Stoners..there will be growers that can help virtually 24/7... everyone is friendly and don't mind helping..
www.autoflower.org
