Fishless cycle question

[Twistersmom]

Yes. I added the salt to the tank, a little at a time, while it cycling. I used 3 tablespoons per each 10 gals. (that will be replaced with the water change) I read this is a good amount for both fish. I wanted to set up a light brackish tank for my freshwater founder, that I did not know where brackish when I bought.

 

[SuBXeRo]

it happens after i do a gravel vac as i have said above, i do deep gravel vacs, so you suck the bacteria out when you remove the water.

 

[colinsk]

Quite, but removing the water doesn't in and of itself upset the bacteria; it must be something about the water coming back in.

When my 29 gallon was cycling I measured the nitrogens twice a day for 6 weeks. There were some interesting surprises that did not quite fit what the books say should happen. One was ammonia going from 0 to .25 on it's own in a 12 hour period only to go back on its own when the tank was in weeks 2 and 3. It just randomly would run up to .25 and I could not find any cause and effect relationship like water changes or feeding.

Another was when the bacteria were still trying to establish, a 30% water change with my first gravel vacuum caused a ammonia spike that caused me to do a 90% water change 12 hours later.

The third was I had a white haze in the tank. (I am pretty sure when a accidentally spilled some "First Bites" into the tank.) I left it for about 3 days knowing it was bacteria and would pass. I finally could not help myself and did a 50% water change, the next 3 days I had big nitrite spikes and had to do twice daily water changes to keep my parameters.

Since this is only one tank I can't say for sure that there was a cause and effect relationship between my actions and the water parameters. I can only guess.

Now that the tank is established and fully stocked I can do what ever I want and keep the parameters. Including vacuuming the entire gravel and heavy cleaning. I have not ever changed my filter but I have squeezed the biofilter into my new 10 gallon and have washed the filter in old tank water but not on a gravel vacuum day.