I have been using the Serenity Aquatics Turtle Health Block for at least 8 years now and have found the water stays cleaner for longer. I tested this by not using the blocks for a few months. In this time I started to have issues with the water quality and needed to do more frequent water changes.

Good price with delivery for what I think is the best turtle tank health block. I’ve always preferred it to the smaller green Reptile One option that disappears before I have done a full water change and filter clean monthly. I do partial water changes weekly and always use a water conditioner and bacteria stability when I do this.
Fresh water long neck turtle was found on the beach 16 years ago fully grown.
Rethink buying one for your kids!
It has outlived a 13 year old dog that was a puppy when he found it on the beach!!!!

Good price with longevity