# min_flow: Minimum flow rate to support MO2 In respirometry: Tools for Conducting and Analyzing Respirometry Experiments

## Description

Calculates the minimum flow rate into a respirometer required to maintain a high pO2. Useful for ensuring an acclimating animal maintains a normoxic environment. It can also be used to estimate the flow rate needed for a given pO2 decrease desired for flow-through respirometry.

## Usage

 ```1 2``` ```min_flow(MO2, min_pO2 = 90, pO2_in = 100, temp = 25, sal = 35, atm_pres = 1013.25) ```

## Arguments

 `MO2` whole-animal oxygen consumption rate (umol / hour). `min_pO2` minimum pO2 acceptable in respirometer (% air saturation). Default is 90% air saturation. `pO2_in` pO2 of water entering respirometer (% air saturation). Default is 100% air saturation. `temp` temperature (°C). Default is 25 °C. `sal` salinity (psu). Default is 35 psu. `atm_pres` atmospheric pressure (mbar). Default is 1013.25 mbar.

## Value

The flow rate (liters / min) into the respirometer required for the steady state pO2 to be `min_pO2`.

## Note

Keep in mind that most organisms are very stressed upon being placed in a respirometer and their MO2 may be much higher than basal MO2.

## Author(s)

Matthew A. Birk, [email protected]

## References

Steffensen JF. 1989. Some errors in respirometry of aquatic breathers: How to avoid and correct for them. Fish Physiol Biochem. 6:49–59. Equation 8.

`max_MO2`, `flush_water`
 ```1 2 3 4 5 6``` ```min_flow(MO2 = 1000) # What is the minimum flow rate required to maintain at least 75% air saturation in a # respirometer with an organism(s) with an oxygen consumption rate of 1000 umol/h # when the intake fresh water is 10 °C and 90% air saturated? min_flow(MO2 = 1000, min_pO2 = 75, pO2_in = 90, temp = 10, sal = 0) ```