i have a magnesium problem with my plants. i am using a bubbleponics system with a ten gallon res. i am using general hydroponic nutes. i am thinking about just putting more water(distilled water that has a ph of 6.0). is distilled water bad to use because i also have a little sodium starting to build up on my lava rocks that i am using. any advice on gettin sodium out of my water?
How do you know it is a magnesium problem?
This is an example of magnesium deficiency: Growth fairly good; foliage chlorotic and with intervenal necrosis; death of older foliage and severe defoliation.
Here is a pic of a potato plant with mag deficiency:
Also gypsum applications are the usual horticultural method of replacing excess sodium in soils. Adding sulfur, sulfuric acid and other acid (most all fertilizers) will release soluble calcium to form gypsum, which in turn replaces the sodium. Two sodium molecules and one of Calcium Sulfate will create free Calcium and Sodium sulfate which is leachable. Since you are using lava rock im not sure if this would work, but I guess you could try. Epsom salts work great to correct Mag deficiencies. And if you are worried about adding salts to your lava, use a foliar spray instead of adding it right to the rez. Plants uptake nutrients 5 times quicker when applied to the foliage. Foliar feeding is considered especially useful for introducing trace elements, or for "emergency" feeding of plants which are found to have a specific shortage. But in some cases, with tomatoes, for example, it is believed that foliar feeding during flower set causes a dramatic increase in fruit production. Generally speaking, it is recommended that foliar feeding be done in morning or evening, since hot days cause the pores on some plants' leaves to close. (Wiki).
