Chemistry Question

[kiriyama]

Hi I am running a small fry tank, I have been feeding all types of food, I know I am probably overfeeding and I do regular water changes. I was originally using an air pump attached to a sponge filter, I am now using an external filter which I had cycled.
I have been advised of using
seachem's deNitrate
Kent's Nitrate Sponge
has anyone here used any of these products ? If so is there anything I should know ?
Any corrspondence greatly appreciated

 

[the biffster]

i used to use nitrazorb all so
used to use pollyfilter as well
i never had any problems with any of
them was a bit put off by pollyfilter
as it is a use once and throw a way as
were as the nitrazorb it can be recharged
by soaking in water and aquarium salt
and can be used a few times it can also be stored
the same way