Hydroponic Reservoir
How long a reservoir lasts and when to top it up.
About Hydroponic Reservoir
Plant water demand is totaled daily, then the usable tank volume below the refill line is divided by that rate. Letting hydroponic water dive to near-empty shifts EC and pH hard, so a set refill point keeps solution stable.
Formula
Hydroponic Reservoir
Daily use = plants x each; days = refill level / daily use
- refill level
- Tank fraction remaining when you top up
Worked example
With the default values below, Hydroponic Reservoir returns Daily Water Use of 4.00. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Tank sizeminimum 0.1 gal
- 30 gal
- Plantsminimum 1
- 8
- Use per plantminimum 0 gal/day
- 0.5 gal/day
- Refill levelaccepts 5–95 %
- 50 %
Results
- Daily Water Use
- 4.00 gal
- Days to Refill
- 3.8 days
- Top-up Volume
- 15.0 gal
Step by step
- 1Values used
- 2Hydroponic Reservoir
- 3Daily Water Use= 4.00 gal
- 4Days to Refill= 3.8 days
- 5Top-up Volume= 15.0 gal
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Hydroponic Reservoir calculated?
Daily use = plants x each; days = refill level / daily use Plant water demand is totaled daily, then the usable tank volume below the refill line is divided by that rate.
Why does Hydroponic Reservoir matter?
Letting hydroponic water dive to near-empty shifts EC and pH hard, so a set refill point keeps solution stable.
What values do I need to enter?
This calculator takes 4 inputs: Tank size, Plants, Use per plant, Refill level. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.