For those still using IFTTT method and having more than one blue connect this may be of interest.
I have two blue connects. One for a pool and one for a reef tank aquarium.
You need to specify the ‘pool’ in the Blue Connect IFTTT. There is only one IFTT webhook integration available.
You can still support two devices by passing in the ‘pool’ identifier and using its value to branch the automation actions in HA.
For example in the json of the webhook add:
"pool":"{{SwimmingPoolName}}"
Then use that value to decide which input_numbers to update. For example: