Experienced beginner!

[mousey]

So Hubby had a thought-- you are not actually 'cycling' because you are adding all the bacteria needed. Therefor you are not 'cycling' at all.

[ron v]

mmmm, OK. But are establishing a cycle. The nitrogen cycle. Maybe we use the wrong terminology. Maybe instead of saying we are "cycling" an aquarium, we should say we are establishing a cycle.

[Toshogu]

correct.... (because I need to type extra stuff to do a quick reply)

[ron v]

Quick update: Day three. Both tanks are showing a tiny bit of ammonia. Less than .25ppm. The PH is down in both from 6.8 to 6.4. The PH issue is expected but is a concern. If it drops much more there won't be any cycle taking place and I don't know what will happen in the Stability tank. KH and Gh are very-very low (less than 50ppm). Maybe I should try to buffer the water but I hate to do that. What do ya'll think?

[emc7]

Throw in a 1/4 tsp of baking soda and retest the kH & pH. It is buffering, but if your goal is a stable aquarium rather than scientific data, you may need either to buffer or step up water changes. IME a TDS < 75 ppm is likely to be associated with an unstable pH and a TDS < 40 definitely will.

[emc7]

I've heard some substrates will reduce nitrates. Maybe by ion exchange.

[TheOldSalt]

Denitrification = bacteria convert nitrate to nitrogen gas. This is good. This happens in those areas of the tank where there is little oxygen.

Reduction = bacteria convert nitrate back to nitrite or ammonia. This is bad. This happens where there is NO oxygen.

[ron v]

the "no oxygen" bacteria is what I know as anaerobic bacteria. Right? I didn't know about the denitrification. Is this significant? Does it occur enough to affect the need for water changes?

[TheOldSalt]

Actually, denitrification is crucial to the success of saltwater reef tanks, and still very handy for all other tanks. We haven't really bothered with developing it in freshwater, though, because freshwater water-changes are cheap & easy. In saltwater it's not so cheap & easy, so we had to figure out a better way. It works quite well, and yes, it eliminates the need for water changes due to nitrate. ( alas, there are a lot more things than nitrate building up, so we still have to change water )
Denitrification should be considered the actual last step of the "cycle."

Reduction is what you get if, for example, the power goes off for several hours and the flow stops in your filter, especially a canister filter. This is why you don't just reactivate such a filter after it's been off awhile; you'd only dump ammonia into your tank.

[ron v]

Todays results are in. PH continues to drop. Down to 6.0 in both tanks. It may be even lower than that. 6.0 is as low as my test kit will go. I need to pick up a low range kit. This is a big problem. At this point I'm probably not getting nitrification so the cycle is at a stand-still in the "no Stability" tank and in the "Stability" tank the bacteria are probably dormant. I guess I'm going to have to buffer. I expected this to happen but was hoping it wouldn't.

[mousey]

TOS please remind me what to do in the event that the power goes out for several hours and I have a canister filter.
What steps should I take before I restart it?

[ron v]

Just rinse it out. You don't want all the gunk that has started to go anaerobic in your tank.

[mousey]

ah, relatively easy to do!

[ron v]

Day five. Some interesting things happening. The "no Stability tank" is starting to cycle. Seems very quick so I am dudious but I have new test kits so here is what it says. PH is at 6.0 or less, TDS is 200, Gh-35, Kh-35, Ammonia-trace, nitrite-.25, nitrate-5.0ppm.
The tank with Stability is TDS-200, Gh-35,KH-35, Ammonia-.25, Nitrite-0 and Nitrate-0.

[ron v]

Day six results. Tank without Stability. Ammonia-1.0, nitrite-1.0, nitrate-5.0.
Tank with Stability Ammonia-0.5, nitrite-0, nitrate- less than 5.
I don't know what it means folks. I'm just reporting the results. One thing I will say. The results seem all over the place. There doesn't seem to an even increase or decrease in readings as you would expect. These test kits are just not very accurate. I think all we can hope is for a general idea of whats going on. What I think we can say for sure is that the tank without Stability is cycling. Actually it seems to be cycling much faster that I would have thought. We are already producing significant amounts of nitrate at only six days. The "Stability" tank has shown little or no ammonia or nitrite which is as advertised. Today tho, we see a small amount of nitrate, which is a little unexpected.