[flyin-lowe]

I have a 120G tank that I just finished cycling (pics in the gallery) and today I started stocking. My plan was corys, a large school of cardinal tetras, and about 8 angels. The guy at the LFS (I don't always trust them but this place seems really good) said that in Indiana the water is way to hard for cardinals and said that unless I am running RO water I would not be able to keep them alive. So I started reading and see that a lot of people can't keep these fish alive. Once my tank is established are these fish that hard to keep? I was originally going with neons but was told that the cardinals get bigger and the angels will be less likely to eat them. The guy at lfs said the neons are hardier and I would be more likely to keep them then cardinals. He said either species will be a meal for the angels once they get big enough and decide they want to eat them. What do you guys think? I just thought it would be awesome to have a school of about 30 of them in a planted tank.

 

[Dmaaaaax]

I disagree 100%. Cardinals are more hardy then neons and less suseptible to neon tetra disease. They get bigger, are more colorful, and can hold themselves in a tank with angels. The more you get the better, because schooling fish find safety in numbers. They will also school better if they see the angels as a threat.

They do prefer lower pH and mid to low GH. I would say pH from about 7.2-6.0 and GH from about 2-8.

 

[flyin-lowe]

My pH is a little all over the place right now in the new tank. I am not sure why. When I test my tap water it test 7.4 on the high range and 7.6 on the standard API kit. After I added it to the tank I tested the tank water and it was about 8.2-8.4. After a few more days the test kit is turning pink which is not even a color on the chart. My kit is new and not expired. After I do a decent size water change it will test around 8.2 again but a few days later pink. I am assuming that pink is off the charts high. I am not sure how high pH can get but the corries I have in the tank have all been doing great for several weeks. I had some rocks in the tank that I think were limestone and I removed those thinking they might be raising my pH. That hasn't helped either, not sure what to do next.
I got a GH test kit last week and my GH is testing between 0-2. Doesn't the low GH leed to swings in pH?
Thanks

 

[dave in Iliamna]

Do you have an ammonia test?
Did this start with the addition of fish?
It is possible that it is caused by out gassing, but I would be conserned over the possibility that it could have to do with ammonia.

 

[flyin-lowe]

The tank is fully cycled. I forgot to update this post. I re tested my tap water and this time I used an airstone and let it sit. Once is sat for over 24 hours it went up to about 8.2. So that is pretty close to what I am getting in my tank.