Cycling Log

[mark.w.jones]

I always thought the adding food method was crap to be honest. Only really worth doing with prawns like Wilder suggested but even then it's a bit hit and miss. At least with a bottle of ammonia sol. you now exactly how much you are adding to your tank each time. Keep up the good work.

oh and to TFF abut the way

 

[Majjie]

I think it's looking good Ben
Just keep your nerve, don't let the ammonia level fall to 0 for any length of time and yes, it's probably easier to add straight ammonia when you need to.

 

[Benauld]

Hi everyone,

Well I'm afraid things have gone t*ts up! My ammonia had shot up to 7ppm two days after I finished dosing food, my nitrite was slowly declining at around 0.5ppm (never got very high in the first place), and my nitrates had fallen from 15 to 10ppm!

I was confused to say the least, then I noticed a funny smell coming from the water. Looking more closely some of my sand was discoloured so I stirred it up and it stank! The only explanation I can think of is that I was creating a better home for anerobic bacteria than denitrifying bacteria, and that the nitrates were being broken down back into ammonia. Anyway, the short story = tank now emptied. I'm going to replace the sand with gravel (I will never use sand again!) and start over next weekend.

My pH was fine 7.5, but even though I soaked my bogwood (for about two weeks beforehand) it produced a LOT more tannins than I had expected. Does anybody know whether tannins per se would cause any problems for colonisation of nitrosomas & nitrobacter?

 

[Majjie]

Sorry to hear that the cycling didn't work out Ben. Although I wouldn't let it put you off sand altogether. I think exactly the same thing would have happpened in gravel.

Like I said before, I've never tried cycling with food - but I think those who do only use a pinch or so a day and don't try to get the ammonia level up very high. The problem with adding a lot of food is that you'll have a lot of organic matter that isn't being used by the nitrifying bacteria - and this just encourages all sorts of other bacteria - as you found out

Incidentally the nitrate isn't converted directly back to ammonia. Anaerobic denitrification results in the formation of nitrogen and nitrous oxide - both gases.

I guess tannins from bog wood could be inhibitory to bacteria but I doubt if the concentrations in your tank would be enough to cause a problem - especially if the pH didn't go down very much. It's far more likely that the build up of organic matter from the decaying food inhibited the nitrifying bacteria.

Better luck next time - I guess you'll be using ammonia from the bottle