How often must be changed?
200610
About every 2 weeks is the recommendation in the instructions, but if the cats drop crud in the water or other circumstances change, it might vary a bit.
200611
I change my charcoal filter about every six weeks and the foam filter every other time, but I put the foam filter in one of the silverware baskets of my dishwasher and wash them. I figure that the very caustic dish washer soap (with clorine) that I use will sterilize anything. My cat has not sufferd any ill affects. Maybe if you had several animals using the fountain, you would want to change them more often.
899675
I've bought them for my son. He told me that you should change them every three months.
194024
I would think changing it would not be an issue for quite a while. I only use it once per month. The current filter should stay good for a long time at that usage rate. When the time comes, I will rinse the filter and put back in for as long as I can.
2095672
It depends on how many people you have in your house. If you have a full family of 4 or 5 or more, once a year. We have 2, I replace every other year.
2247771
My wife and I only have to change it every 6 months, I'd say 4-6 months would be your average. Works great BTW
677255
I heard from a professional that they should be changed annually, sonthey probably last a bit longer...
1942112
According to the manual, a canister typically needs to be changed once a year.
1485214
I replace mine once a year. A lot depends on how clean your house is and if you have pets that shed hair. I have two cats.
861138
I have changed the DE as little as twice per season and as much as four times. It all depends on the type of season we are having in upstate N.Y. Wind, dust and pollen in the air, how often the pool is used and water temperature.
1463460
There's not one answer to this question. It depends on the environment you live in and possibly the allergy sensitivities of people in the home. It's good to check them every month or so. We live inside a hardwood forest and it seems to me, we have to change ours about every 3 months or so. You can tell when they need changing, just by looking at them. If your environment has a lot of dust or other particles in it, you may need to change it every month. On the other hand, you might be able to go six months without changing it. Hope that helps some.
269485
I change mine every 3 months regardless.... directions say every 3 months also.
31866
you know when to change it -- you will suddenly stop hearing, even with a good battery. frequency varies by the person. for me, it is almost the same frequency as the need for battery replacement -- once per week.
1857862
Changing the filter depends on how often you use the coffee machine. We change ours about once every 18-24 months because we do not use the machine very much (about 2 - 3 times a month). You could also gauge the changing time by how the coffee tastes. If you make it the same every time and you notice it tastes a little different, you probably need to change the filter.
985495
I think they recommend once a month. It depends on how frequently you use it.
425639
It takes double A bateries, yes you have to change them so often depending on how long you run it.
1330432
Their literature says that the batteries and the sensor should be changed once per year. I have owned these instruments about 25 years and have found that every 2 years is just about right. I google, ( and now Amazon ) look at price and then buy
270596
In the Instructions it says when to change, I think once a year under normal use.