If the plant is perking up then that's good.
Half of me is telling me that it's not a good idea to keep changing the water though. What you want to do is stablise the conditions so that they are appropriate, not keep the plant guessing as to what is coming next. The stable and healthy conditions involve getting lots of Carbon Dioxide into the water. Peat water will increase acidity and help against algae, but what is ultimately needed for optimum growth is decomposing plant matter on the bottom. This releases CO2 as it decomposes, keeping the water mildly acidic (Aldrovanda doesn't need acid consitions incidentally), but more importantly providing the CO2 that the plant seems to thrive on.
I use sedge litter as that is what is classically recommended, and is replenished naturally by the carex and typha that is growing in the tank. It also releases humic and tannic acids into the water, which are a good source of nutrients for the plant. I have also grown it with simply a bunch of leaves from some garden plants (mainly ceanothus) at the bottom of the tank above the peat. Some growers empty the sludge from their water trays into the tank.
Companion plants are also useful becuase they extract nitrates which would otherwise fuel algae.
Do you know if yours is a variety that will want a winter dormancy or not?