Different Tank's water chemestry?/crossposted from sick fish

[ashesofyou]

I have 3 tanks in question... one 10 gallon, a 45 gallon, and a 50 gallon...

I understand that in different points in your cycle, there will be different water chemestry, but will it differ as much as mine?...

Here are the stats:
Tank #1
45 gallon
9 zebra danios, juvinile (to cycle, has been with fish for about 3 weeks)
NitrAte: 20ppm
NitrIte: 5.0ppm
Total Hardness: ~15
Total Alkalinity: 0
PH: ~6.8

Tank #2
50 gallon
7 zebra danios juvinile (to cycle, has been with fish for about 4 days)
NitrAte: ~5ppm
NitrIte: 0ppm
Hardness: 100
Alkalinity: 80
PH: ~6.7

Tank #3
10 gallon
4 African Dwarf Frogs, 1 cory catfish (has been up and going for 2 months since a move, kept the gravel wet to retain bacteria, before that had been going for about 2 months and had just cycled)
NitrAte: 30ppm
NitrIte: 0ppm
Hardness: 10
Alkalinity: 60
PH: 6.4

Directly Out of Tap:
NitrAte: 0ppm (duh)
NitrIte: 0ppm (duh)
Hardness: 35
Alkalinity: 50
PH: 7


My question is... is it normal for tanks in the same house to vairy so much in their water chemestry? I know they will go through an adjustment period until everything settles, but why would hardness be 100 in tank #2, and only 10 in tank #3? It doesn't seem like the hardness would differ that much!

Also... in tank #2, it has only been up and going with the fish added about 4 days ago... why am I already showing nitrAtes? I had my water tested at my LFS, and he said that if he didn't know any better, he would say that the tank had already cycled... (I can see why, no nitrItes, but a small number of nitrAtes)

In tank #2 I lost 4 zebra danios this afternoon who were doing very well earlier this morning. Went to do my evening count, and there was one floating, and three stuck to the filter, leaving me with a total of 7 live. They showed no sign of illness, and I could see nothing unusual on their bodies. Any ideas on what could have caused it?

I took a sample of this water to my LFS, as I had just noticed my liquid tests were expired... (no wonder they were giving wacky results). Everything was "right on" the results I have posted here for you, but at the LFS, my PH tested around 8.4 or higher. (off the scales)... I got new test strips, and now here at home that same tank is testing at about 6.7. Thought that was a bit odd... anyone have input?

Thank you sooooo much, and I'm sorry my posting is so long, but I would rather give too much info, so everyone can get an educated guess, than not enough, and make you shoot in the dark

If you need anything else to get an idea of the situation, let me know!!!
(oh, and sorry if there are any spelling errors, I'm using the opera browser, and the spellcheck won't work :-( )

 

[fishfreek]

I would retest on the 55 to see if you get the same result. Was this 55 a used tank? If so what was it used for prior?

Your not testing for ammonia. Is there a reason for not testing ammonia? Its just as deadly as nitrite and it comes before nitrite so you would have to have ammonia first.

My guess is your fish are dieing due to ammonia in tank #2. Did you use any gravel from the established tank in the other two tanks? If so this would explain where the nitrate could have come from. Using a cup or two of that gravel would also speed up the cycle process.