Additives? which ones?

[Rikko]

Originally Posted by geeeman

I see that knowbody seems to mention adding Cycle. Is this not required? I have been adding it to my tank for the last 7yrs.

The only people who have told me that you need Cycle (or related brands) are the company who makes it and people who have been told that by the company that makes it.
I've never used it and have never been convinced that it has a substantial effect. (I can't be bothered to argue against 'But I added it and 4-6 weeks later my fish stopped dying!' anymore) The most generous I'll be re: biological supplements is that they probably aren't doing any harm.

A couple papers have surfaced that analysed mature filter beds and they weren't even able to culture nitrosomonas and nitrobacter from it.. Looks like they aren't even present in adequate numbers in a mature filter bed. Nitrospira are present, but they don't seem to have a solid enough understanding of a mature filter to explain it satisfactorially. I believe the chief science officer (or some similar sounding position) of Marineland is the author of one such paper. Another was a different source but I lost the link long ago.

My rule of thumb for adding "product" to my tanks is that if a company tells me I need it, I definitely don't; and if the scientific reasoning behind it (ie sodium thiosulfate to neutralize chlorine in municipal tapwater/calcium chloride or calcium hydroxide to bolster calcium levels) is well understood, I can probably find a cheaper and more controllable solution outside of the market.