What duty cycle are these pumps people are recommending rated for?
Typical peristaltic pumps should be rated for the duty cycle you intended to use. A pump that can run for multiple hours or more doing a continuous water change is general not the same as one for dosing precise amounts of additives.
Lab and industrial grade pumps publish information on the supported duty cycles and whether it is approved for continuous duty.
Not saying it won't work, but you're definitely shortening the lifespan of your pump.
I'd also look at a unit with dual heads on a single motor where you can configure the direction of each head. Then you can have one draining and one filling at the same rate.
I would also recommend thinking about accuracy as a relative measurement of confidence. If you are doing a 3gal water change you probably don't need a pump that is accurate to the tenth of a milliliter. Think about it terms of percentage; generally 1% is a very acceptable error margin.
Typical peristaltic pumps should be rated for the duty cycle you intended to use. A pump that can run for multiple hours or more doing a continuous water change is general not the same as one for dosing precise amounts of additives.
Lab and industrial grade pumps publish information on the supported duty cycles and whether it is approved for continuous duty.
Not saying it won't work, but you're definitely shortening the lifespan of your pump.
I'd also look at a unit with dual heads on a single motor where you can configure the direction of each head. Then you can have one draining and one filling at the same rate.
I would also recommend thinking about accuracy as a relative measurement of confidence. If you are doing a 3gal water change you probably don't need a pump that is accurate to the tenth of a milliliter. Think about it terms of percentage; generally 1% is a very acceptable error margin.