Hydroponic Reservoir Refill Calculator

In an indoor grow reservoir, you frequent notice the water level has dropped. The pump starts sucking air; no more water. It’s starting to sputter, plants becomes thirsty, and the pump is gasping for air. To rescue the system, you run around with a jug of water. With some planning, this is avoidable.

Reservoir management are a matter of organization. It’s not just a matter of gardening. It’s a miniature chemical plant, and it use up its raw materials. The trick is to know what the water level mean in that plastic tote. We all know most growers are thinking about nutrients; nobody think about the water, which is what plants actualy drink.

How to Manage Your Water Reservoir

As the water drips down into their leaves or evaporates from the growing medium, it concentrate the rest of the solution. That solution has a different electrical conductivity (EC), known as its “drift”, based off the concentration of those dissolved substances. The goal is to achieve your desired EC strength, and the calculator above tell you precisely how much plain water versus nutrient-rich solution you need to add to hit your target strength.

It sounds easy, but the dilution effect can be tricky. For example, if your existing EC is greater than your target, don’t increase nutrients. Instead, you must dilut. The tool will calculate specific gravity for you; you won’t have to do the math.

Another crucial figure is pump reserve. All submersible pumps has a minimum depth they must be immersed. Below this mark, they pull air, overheat and fail. Ouch! That’s costly. So you’d better know your setup’s number before water level reaches it. Pump requirements is listed in the reference table.

To prevent cavitation, common pump types range from one-half of a gallon (for small fountain pumps) to as much as ten gallons (in larger systems). But the reserve is needed for more than keeping the pump cool. It keeps the roots fed, too. When water movement stop, oxygen in the root zone drop. Root rot follows starved roots, and that’s hard to reverse once it takes hold.

How much do you think evaporates? That depends heavily on where it’s stored. Water evaporates quicker from a warm greenhouse during the summer different than a cool basement over the winter. Enter an approximate % of evaporation rate into the calculator and see how long that water is going to last you right now.

Notice, don’t panic. Learn when it is time to act before it is too late. Go from being in a reactive scramble mode to being in proactive scheduling mode. Set a reminder to check back 2-days ahead of the trigger point so you’ll always have a buffer.

Each crop take up water differently. One head of lettuce might take a while to drink, but a full-on tomato plant may consume upward of half a gallon a day. If you’re guessing the wrong amount, it’ll throw off when you think the reservoir need refilling. The tool has some preset estimates based off common setups: large totes, vertical towers, etc. Use those as a starting point.

Check how much you actualy go through, too. Do you find yourself filling faster than expected? Your environment’s probably wetter/hotter than expected. Tweak the inputs, reconfigure the settings.

Consistency. A consistent water level mean a consistent oxygen supply and consistent nutrient concentration. This ensures there are no surprises for the plants. No surprises for you. Go check the tank calmly, not nervously. You’ll know when it reaches the bottom, and you’ll know how high it is at any given moment. That’s peace of mind, and it’s not too much time to spend plugging some numbers into a calculator.

Cover the pump. Maintain a constant water level. Allow the plants to grow uninterrupted.