Fishless cycling just won't end...

[gali]

It's me again, with yet another question about my cycling tank
For those who haven't been following, it's a 38g, today's day 25.
(The trip I planned, btw, was rescheduled, so I truly hope this cycle ends soon so I'll be able to leave and not worry.)

Ammonia: 0 on days 12-21, day 22: 0.25 day 23: 0.5 day 24: 0 day 25: 0.25
Nitrite peaked at 3 on day 6 and gradually came down, to somewhere between 0 and 0.25 in the last 4 days.
Nitrate appeared on day 3, has reached a reading of 7 on day 12, and has been about 8 since.

I'm using AP's master kit. I suspected the kit at first but used it to test my 10g water and got nice results - am 0 ni 0 na 10, so it seems to be ok.
To be on the safe side, I'll take a sample to the LFS tomorrow.

I've had some issued with low KH and pH crashes due to that. I've been adding 2-3 teaspoons of baking soda almost daily since day 9.

So, I'm quite unhappy about the ammonia reappearing, and also about the stuck nitrate levels. Any idea what's going on ?

TIA

 

[Beeker]

That happened to me too. The ammonia and nitrites reappearing is because of the PH and KH crash. You don't need too much baking soda. Check your Ph and KH. Ideally, you don't want it lower than 3 or higher than 8. Once you get those back up, which is immediately after you add the baking soda, you should be back on track. Once your KH is around 6 and your Ph is around 7 (again, these numbers are ideal but not necessary to be stuck to), you should see the ammonia disappearing again. You can do a water change or two and that will help as well.

 

[gali]

I should have mentioned that my tap water is soft - KH and GH are 3.
I test KH/pH daily and KH is usually 1 or 2, so I add baking soda on a daily basis to bring KH back to 3. It's been Ok so far but I wonder whether adding more baking soda now will help to end the process.

What happens when the cycle is over? Will KH stable at tap water level? My 10g seems to be OK, but now I wonder.

 

[Beeker]

When the cycle is over you do a big waterchange or two and add your fish. The water params should stable out at about your tap ranges and with regular waterchanges you should be able to keep them there. I hope I'm answering your questions. Have I covered it?

 

[gali]

I know I should do a large water change at the end. I can't wait..
I just wonder - since it's bacteria growth that causes KH drops, once the tank is stable KH should stable as well, right?

Anyway, the question now is whether I should add even more baking soda, to bring KH to more than the usual 3. Or will the cycle end with KH at 3 as it has been since the beginning.