Nitrate Issue with Fishless Cycle?

UPDATE

Date, pH, NH3, NO2, NO3
2/20/09, 8, 6.0ppm, 1.0ppm, 0ppm
2/27/09, 8, 1.0ppm, 5.0ppm, 7ppm
3/1/09, 7.4, .25 ppm, 5.0ppm, 5ppm
3/6/09, 6.4, 2.0ppm, .25ppm, 7.5ppm

Can someone help diagnose what's going on here? Tank was started on 2/12 initially.
 
Don't worry about the pH. Biological activity within the tank will eat away at the buffer, lowering it naturally.

Did you add ammonia between 3/1 and now?

You have nitrates so you are moving forward still.

Yup, doing a tad of ammonia almost daily now (tad as in a couple drops).

What should pH normally be at?
 
3/11/09 pm 6.4 / 3.0ppm / 0ppm / 10ppm
3/13/09 pm 6.4 / 4.0ppm / 0ppm / 8ppm
3/14/09 am 6.2 / 3.0ppm / 0ppm / 40ppm
3/14/09 pm 6.2 / 5.0ppm / 0ppm / 50ppm
3/15/09 pm 6.0 / 5.0ppm / 0ppm / 50ppm
3/16/09 pm 7.2 / 2.5ppm / 0ppm / 50ppm
3/17/09 pm 7.2 / 2.0ppm / 0ppm / 60ppm
3/19/09 pm 6.6 / 2.0ppm / 0ppm / 20ppm

Good grief - why won't my ammonia drop off. Plants are doing great and the tiny snail in there seems to be doing great. I haven't added ammonia in a week now... should I restart or discontinue?
 
Actually, pH is an issue; as it approaches 6 the bacteria are inhibited significantly. I'd add some bicarb to bring KH up and raise pH to 7+
 
Actually, pH is an issue; as it approaches 6 the bacteria are inhibited significantly. I'd add some bicarb to bring KH up and raise pH to 7+

is that something I'm going to have to normally do? and why would it keep dropping? I'm concerned about the pH and Nitrates...


Date / ph / Ammonia / Nitrite / Nitrate
3/20/09 am / 6.8 / 4.0ppm / 0ppm / 40ppm
3/20/09 pm / 6.6 / 4.0ppm / .15ppm / 40ppm
3/21/09 pm / 6.8 / 3.0ppm / 0ppm / 60ppm
3/22/09 pm / 6.6 / 2.0ppm / .5ppm / 60ppm
3/25/09 am / 6.8 / 1.0ppm / 0ppm / 30ppm
3/26/09 pm / 6.4 / 0.5ppm / 0ppm / 40ppm

I haven't added any ammonia since 3/20... do I need to keep it higher or let it drop off? I'm glad working on my Cobra isn't this hard.
 
Your normal water changes should be enough to keep the pH up. You likely have water with very little carbonates. The extra protons created in the reduction of ammonia to nitrate are converting your CO3 (carbonate) to CO2. I'll spare you the pathways (and me from looking them up).

The good news is your tank is almost cycled. When you are adding ammonia every day and the readings are 0 ammonia and 0 nitrites by the next day then do a big water change (90%) and you are ready for fish. Then change about 20 to 30 percent every week and you should do fine.
 
Your normal water changes should be enough to keep the pH up. You likely have water with very little carbonates. The extra protons created in the reduction of ammonia to nitrate are converting your CO3 (carbonate) to CO2. I'll spare you the pathways (and me from looking them up).

Ok, maybe that's the problem. I never initiated water changes as stated above on the second post. Maybe there was just a misunderstanding on my part (likely).
 
You don't need to change water till you get down to 6.2pH or you start adding fish. With harder water you can go all the way through a fishless cycle with no water changes.
 
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