I have been using ffof for my first 4 grows. I've decided to go the organic route this time to save some time and money on nutrients. I'm using coast of maine platinum growers mix. Like my previous grows, I'll be using ro water. My questions are, should I add Cal mag to my ro water since the reverse osmosis system strip the water of calcium and magnesium? Or will the soil be able to provide those nutrients? Should I adjust the pH? Or will it adjust itself? I'm growing from seed in a 5 gallon smart pot to avoid transplanting. They are starting their 3rd set of leaves so I haven't exactly watered the pot enough to get a run off so I haven't been able to check the run off.
Just wanna make sure my girls are getting what they need from the get go
You can get try to away with adding in a dry sources of cal and mag but it takes time to break down and become available to the plants. I agree with others here who are saying don't even bother worrying about ph; it's almost a non issue in organics.
I suggest using other minerals besides Epsom salt like garden gypsum, crushed oyster shell, and dolomite lime. I add all three to my recycling soil plus I compost eggshells from a a worm bin. A supply of compost is often overlooked by organic noobs and is the most important element IMO; a supernaturally active mix keeps your plants healthy and green even if NPK values are relatively low. Microbes can consume every bit of organic material present in a container as long as there are large healthy populations of them; regular applications of AACTs will maintain their numbers. Most times a deficiency is in fact due to a lack of microbial activity; there are still nutrients in the soil waiting to be consumed by the microherd and made available for uptake.
Cal/mag helps to absorb all other nutrients and its not always readily available in a mix that has not been amended and recycled a few times. It can take a year or longer for some minerals to break down and become available in the soil. So because of this I say yes to adding a liquid preferably organic cal/mag at least until you can recycle & amend the soil a few times. I use distilled water supplied from a dehumidifier which has like 4 ppm so I add in General organics calmag+ at 6 drops per gal at almost every watering. If I use collected rain I add nothing as it usually contains macros and microbial life. The key is to give plants clean water that is about 25 ppm. Rainwater is the shit btw...
Dont avoid transplanting; potting up as the plant develops gives opportunity to add granular mycorrhizae on the roots and to add in fresh mix and compost. I pot up as needed until just before flipping to bloom phase. Then push in 2 jobes organic spikes into the final size pot which feeds through to harvest time.
