When I first put the Seresto collar on my cat last November, both she & I experienced marked systemic issues including lethargy paradoxically paired with agitation. I thought it was just a phase & that we just needed to get used to it. This reaction did lessen some in a few days, & then I started experiencing an extremely itchy skin reaction with angry red sores. After 10 days I removed this collar from my cat, but there was already so much of the residue from the collar in my home that I had to deep clean everything she came in contact with to try to get rid of it. The packaging does warn that if you are sensitive to the ingredients of this product (Imidacloprid & Flumethrin) you will become increasingly sensitive to it. Well, I did, & as I started reacting to smaller & smaller amounts, it seemed no amount of deep cleaning was enough to remove it all. I cleaned everything in my house for one month, & ended up having to discard some things like pillows & a mattress that the "dust" released by this collar got into that I could never completely wash out. The collar is designed to last 8 months & so its chemical residue is extremely sticky & it seems to want to cling to everything, including the sponges, mop, wash rags, & sink basins I used to clean it up, making it extremely hard to completely get rid of compared to normal household dirt.

Like so many other reviewers here, I would like to add my vote for this as the best water conditioner available. A little bottle will last you a long time, even if have a big tank and do lots of water changes. This 500 ml bottle is enough to treat a 55 gallon tank that gets weekly 20-30% water changes for nearly two years. If you have a 20 gallon tank or something smaller, you might do better to just get the 

Awesome grille! It does scratch easily so beware of that. I sprayed mine with Bedliner to give it a mean look. Highly reccomend!!