Today’s inquiry deals with the EZ Coliform Cult Test for coliform bacteria in water. ‘Pam’ asked, “I bought an EZ Coliform Cult test and read the instructions, but have now lost the instructions. The packaging tells everything except the incubation time and temperature. Would you please give me that information?”
Of COURSE we can assist with this request! The EZ Coliform Cult Test can have either a 24 hour incubation period or a 48 hour incubation period depending upon temperature.
- 24 hour incubation period @ 35C/95F
- 48 hour incubation @ 25C/77F
Why the difference in times for different temperatures? Simple: Biological activity increases at warmer temperatures meaning coliform bacteria, if present, will reproduce faster. As that happens, the increased number of bacteria naturally produce compounds that cause the test to show a ‘positive’ result.
A word of caution…
Coliform bacteria typically come from the waste products of mammals (i.e. humans, warm-blooded animals). If a properly performed coliform bacteria test gives a positive result then we highly suggest having the water source tested by a certified water quality testing laboratory and taking action(s) to remedy the situation if the lab results also come back positive for coliform bacteria.