Editing Hydroponics (section)

===Tools===
====Common equipment====
Managing nutrient concentrations, oxygen saturation, and pH values within acceptable ranges is essential for successful hydroponic [[horticulture]]. Common tools used to manage hydroponic solutions include:
* [[Electrical conductivity meter]]s, a tool which estimates nutrient ppm by measuring how well a solution transmits an [[electric current]].
* [[pH meter]], a tool that uses an electric current to determine the concentration of [[hydrogen ion]]s in solution.
* [[Clark electrode|Oxygen electrode]], an electrochemical sensor for determining the oxygen concentration in solution.
* [[Litmus paper]], disposable [[pH indicator]] strips that determine hydrogen ion concentrations by color changing [[chemical reaction]].
* [[Graduated cylinder]]s or [[measuring spoon]]s to measure out premixed, commercial hydroponic solutions.

====Equipment====
Chemical equipment can also be used to perform accurate [[chemical analysis|chemical analyses]] of nutrient solutions. Examples include:{{sfn|Douglas|1985|p={{pn|date=March 2025}}}}
* [[Weighing scale|Balances]] for accurately measuring materials.
* [[Laboratory glassware]], such as [[burette]]s and [[pipette]]s, for performing [[titration]]s.
* [[Colorimeter (chemistry)|Colorimeters]] for solution tests which apply the [[Beer–Lambert law]].
* [[Spectrophotometry|Spectrophotometer]] to measure the concentrations of the key parameter nitrate and other nutrients, such as phosphate, sulfate or iron.
* [[Containers]] for growing and storing the plants.

Using chemical equipment for hydroponic solutions can be beneficial to growers of any background because nutrient solutions are often reusable.<ref name=Reuse /> Because nutrient solutions are virtually never completely depleted, and should never be due to the unacceptably low [[osmotic pressure]] that would result, re-fortification of old solutions with new nutrients can save growers money and can control [[point source pollution]], a common source for the [[eutrophication]] of nearby lakes and streams.<ref name="Reuse">{{cite journal|last1=Kumar|first1=Ramasamy Rajesh|last2=Cho|first2=Jae Young|title=Reuse of hydroponic waste solution|journal=Environmental Science and Pollution Research|date=2014|volume=21|issue=16|pages=9569–9577|doi=10.1007/s11356-014-3024-3|pmid=24838258|bibcode=2014ESPR...21.9569K }}</ref>

====Software====
Although pre-mixed concentrated nutrient solutions are generally purchased from commercial nutrient manufacturers by hydroponic hobbyists and small commercial growers, several tools exist to help anyone prepare their own solutions without extensive knowledge about chemistry. The free and open source tools HydroBuddy<ref>{{cite web|url=https://scienceinhydroponics.com/2016/03/the-first-free-hydroponic-nutrient-calculator-program-o.html|title=HydroBuddy v1.62: The First Free Open Source Hydroponic Nutrient Calculator Program Available Online|date=Mar 30, 2016|website=scienceinhydroponics.com|language=en-US|access-date=Nov 22, 2018}}</ref> and HydroCal<ref>{{cite web|url=https://sourceforge.net/projects/hydrocal/|title=HydroCal: Hydroponic Nutrient Formula Calculator|date=Feb 2, 2010|website=SourceForge|language=en}}</ref> have been created by professional chemists to help any hydroponics grower prepare their own nutrient solutions. The first program is available for Windows, Mac and Linux while the second one can be used through a simple JavaScript interface. Both programs allow for basic nutrient solution preparation although HydroBuddy provides added functionality to use and save custom substances, save formulations and predict electrical conductivity values.