Small Fish, Big Pond

The reservoir for this system only holds 10 gallons and in the recent heat the plants go through about 3-4 gallons of water a day. But because of the way hydroponics systems work as the nutrient passes over the roots they absorb the water and what nutrients they need. The rest drains back into the system and is recycled.

So while the water may be run through in a couple days, the nutrient lasts a couple weeks.

After a couple weeks the water is no longer providing anything but moisture. Plants will still grow, the majority of their mass actually comes from the CO2 they absorb from the air, but without the extra nutrients the growth is slow and stunted. So we have to dump the old depleted nutrient and put in new.

It’s best to dump out the depleted nutrient rather than keep adding more to the system, some nutrients may have been used less so you could end up with high Phosphorus content or something. Just dump the reservoir out on the lawn or soil garden and mix a fresh batch.

Before I dump out the nutrient I usually turn the system on to get a fresh layer of moisture on the roots. It only takes about 10 minutes to dump and refill everything but I’d rather not run the risk of drying out the roots too much. The more shock and abuse the plants suffer they slower they will grow.

First step is to dump out the old. The problem is that you don’t want the pump to get dirty so I like to put all the gear into a small tray to keep it off the ground. It’s also a good time to back wash any filters you can get to.

I mix the nutrient in a small bucket so I can get it all to dissolve (it’s a solid water soluble fertilizer). The ratio for this is 1tsp fertilizer to 1gallon water.

Get it all dissolved in a small amount of water. Now it’s super concentrated liquid fertilizer; in reality this is probably still more diluted than liquid fertilizer you spray on a normal soil garden.

Then rinse the equipment and reservoir off. And reassemble.

Pour the nutrient in, then fill with water till full. Before leaving it alone I like to check and balance the pH levels since with new nutrient it can be a little off (next blog post we’ll cover that).