This was a week of establishment for the basil sprouts. Most notable was the development of the first set of ‘true’ leaves.
These ‘true’ leaves are prominent on every sprout with a second set clearly on the way so it appears that things are going well. The basil sprouts are not burning under the 1000-watt MH bulb (due to it being elevated several feet above the tray) and they appear verdant and turgid. Given their health, I very gradually increased nutrient levels. I continued to use the same regimen of Fifth Season Fulvic Acid, H2O2, and Canna Start, effectively raising the PPM level from 150-200 to 250 (on the standard North American EC-500 scale). The pH was quite low at around 5.1 so I added about 15 ml of Fifth Season pH Up to achieve a final pH 6.0 which should allow good solubility of all essential nutrients.
I also elected to add air stones into the nutrient reservoir. For those that don’t know, air stones are porous terminal attachments- ours look like cylinders- that attach with air tubing to small air pumps. The stones create a very fine bubble profile that drastically increases the surface area of the air moving through the nutrient solution. This is a very simple means of ensuring that the reservoir water contains enough dissolved oxygen. The benefits of aerating the nutrient solution are multiple: Plants benefit directly from having O2 available to their roots; highly aerated water discourages the growth of potentially pathogenic anaerobic bacteria such as those responsible for botulism; the air stone churns the water which helps do distribute liquids as they are added to the nutrient reservoir.
A simple aeration set up looks like this: