[wharfrat]

I have 500ml of purigen with matrix in my Tropheus tank and my NO3's are almost undetectable each week; however, I am unsure about how much for my new 25g cube. Should I just use 2 of the premade bags for surface area in the top of my classic 2217 that I will be running on the tank?

 

[discuspaul]

2 of the Purigen bags at once would be plenty for that size of tank. 1 Bag at a time would likely be just fine.

 

[wharfrat]

Thanks for your response:bounce: