Marineland Premium Carbon-Ammonia Neutralizing Blend

[parl0017]

I'm relatively new when it comes to fish-keeping. Both my aquariums have been up and running for about 3 months. I read before setting up that it's a good idea to purchase a better quality carbon to replace the carbon that comes with your filter. I bought the Marineland Premium Carbon-Ammonia Neutralizing Blend and used it to replace the carbon in both a Cascade 400 internal filter and an Aquaclear 50 HOB filter. However, after some additional reading, I'm wondering if there's any reason I should not be using this blend constantly? I always do weekly water changes, so I'm not using it with the thought that I wouldn't have to do that, I just thought it might be better for the fish. However, I've lost a few fish in one of my aquariums and I'm trying to pinpoint the cause.

 

[54seaweed]

When I kept freshwater fish I swore by a similar carbon to yours .
API Ammo-Carb it worked real well for me and I ran it all the time it always kept water pristine ,
I don't see why you couldn't keep running the new carbon , if I find something that works why would I change it back out ,
there were times I was to sick from kemo to do water changes and the tank would go 6+ months the better carbon saved me .
if you like it run it I always did ,

 

[parl0017]

Yes, I have to say the water in both my aquariums looks wonderful, crystal clear. However, when my cories kept dying, it just got me wondering what's in the pellets that neutralizes the ammonia and if constant exposure to it would be bad for the fish. I didn't really suspect that it was the cause of the fish dying, it just got me thinking! Thanks for your help!