Why do I have such parameter swings in a cycled tank??
 

I'm confused about my constantly changing water results.
The tank is cycled, no new fish have been added in over two months.
I do weekly water changes of 20 to 50%, using dechlorinated spring water. Since the flucuations starting happening
I've been doing water changes every two days,
adding Nitromax each time I'm doing a water change.

It's a ten gallon Eclipse with a small pictus & pleco (2 1/2 " each), 4 neons & 2 danios, all juvenile. The pictus & pleco
are being moved to my 100gl as soon is it fully cycled.

Anyone know what is happening and how I can correct for stable levels?
Thanks for any input!!
Here are my water parameters:

6/18 am Ph 7.4, Am 0.25, Nitrite 1.0, Nitrate 20
6/18 pm Ph 7.4, Am 0.25, Nitrite 2.5, Nitrate 0
6/18 pm Ph 7.2, Am 0, Nitrite 0.5, Nitrate 10 (after 33% water change)

6/19 am Ph 6.8, Am 0.75, Nitrite 0.25, Nitrate 0
6/19 pm Ph 7.0, Am 0, Nitrite 1.0, Nitrate 0

6/20 am Ph 6.0, Am 0.75, Nitrite 1.0, Nitrate 0

Well, if you're getting nitrite readings your tank is not done cycling. What are the parameters of your tap water both when it first comes out and after you age it for 24 hours?

I had zero nitrite readings for the last few weeks, then this started about four days ago. When I get home this evening
I'll take readings from the aged water that I have set aside
and I'll test the water straight from the tap.

The last six water changes have been using bottled spring water, though. Should I do tests on the bottled spring?

hummmmmm :?

Absolutely. Bottled water can definitely contain nitrites as well.