I’ve had 2 gardens in my 2 Farm Pluses growing tomato plants for about 5 weeks. Based on Ginger’s advice I’ve started changing the water in them every week, beginning a week ago. I check EC and pH every day, and you can see that the water chemistry is going bad after about a week in that the pH starts dropping.
Each Farm Plus basin holds about 2.2 gallons of water. It uses the internal pump and a plastic hose to drain the basin, which takes 10 minutes or so and doesn’t require attention. The connection for attachment of the hose is in the middle of the deck, and can be difficult to reach with several tomato plants or a full deck of lettuce growing. But so far the drain and refill has been relatively painless.
When you refill the basin with water, you have to add a new charge of nutrient. One of my tomato plants is flowering, and I keep the EC at 2.2. (I’m using AG nutrient). It requires about 38 ml of nutrient to bring the fresh water to EC=2.2 in one of the basins. Together with a little nutrient that I add during the week to keep it at 2.2, you can see that growing tomatoes consumes a lot of nutrient. I’m expecting the need to drain and refill more often when I actually have tomatoes growing.
Lessons learned? When it’s time to replant I think I’ll limit the tomatoes to one garden on the Farm Pluses. I’ll switch the other garden to all peppers. The sweet pepper and poblano pepper plants are doing fine, though neither has flowered yet.