Is It Safe To Use A Liquid Nutrients For Kratke Passive Hydroponic Growing Indoors (water, Epsom Salts, Calcium Nitrate, & NKP Mix

Question

at 4-18-38) We use approx 6-12 grams of each of the following fertilizer ingredients per 5 gallons of water and generally only grow using that much total liquid for ALL of our small indoor lettuce & herb garden at any one time (approx 20 quart size containers of the liquid mixture). We live in hot zone 10a so we grow them indoors all year round and have central air conditioning running frequently about 6-8 months per year. If we put the grow racks in a spare room that is dedicated for that purpose but does return air throughout our homes ventilation system, is there any chance we would reach any kind of toxic levels or have to worry about respiratory or other health concerns from this type of set up? we have noticed in the past that there is obviously some very slow reduction of liquid in our containers throughout each approximately 60 day growing cycle, however we’re not sure how much of this could be attributed to evaporation into the air versus the plant using up the liquid for its growth and development.

Answer 1

It is, completely, fine! Solids will not evaporate from your liquid reservoir. Only liquids will. With this being said, you will need to keep an eye on your nutrient levels. If your plants are not using them as fast as needed, then the levels in your water will be too high.

https://www.gardeningknowhow.com/edible/vegetables/lettuce

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-moisture-in-plants.htm

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soil-ph-plants.htm

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/test-soil-for-pests-and-diseases.htm

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/making-sure-soil-drains-well.htm