Severum Hiding, not swimming

Question
Hi.  I've a new tank. It's 122lts, set up over the past week.  Has a waterfall filter, with carbon, ceramics and sponge currently.  I don't know the ph or nitrate levels.  Temp is approx 24C.

I have 6 baby severum in it, (and two goldfish- I know it's not right) and they were fine till today.  I came out and they were all at the bottom of the tank, hiding, fins clamped.  Theer were bubbles on the surface, so I did a 50%water change and cleaned the filter.  They don't appear to be scratching, breating particularly quickly, or showing other outward signs of distress I recognise.  One fish has seperated itself off from the others, and I'm concerned about it.  AFter the water change the fish perked up for a bit and swam around, but now they are loosing their interest again. Two are sitting at the top of the tank.


Answer
Hi Dale: New tanks often encounter spikes in water chemistry that are toxic to fish.  I would invest in a test kit so that you can monitor at the very least the ammonia level.  Read up a bit on the nitrogen cycle so that the water tests make more sense to you.  Severums are cichlids so they will hide and find spots to defend.  The question to ask is whether or not they are hiding because the tank is toxic or if they are just being cichlids... The fact that two are sitting at the top of the tank indicates to me that the tank is toxic.  You are going to have to change water again about 40%.  I hope that you are using water conditioner when you add in the new water so that the chlorine is removed.  You can take your water to most aquarium stores and they will test it for you.  It is usually a free service. Anyway... change the water, get your water tested and then get back to me with the chemistry values.  You can also look into adding beneficial bacteria to the tank as well... dave