4 of my new tetras died

Question
QUESTION: Hi Renee, I recently mailed you about a new fish moon pod. We filtered it for a week, and then I put in some food in to start a fishless cycle a little. We stocked the tank with 1 betta and 5 neons on Saturday 22nd January. They seemed to thrive for a week, feeding them lightly once a day with tropical flake but then gradually from Friday 28th we have had one neon weaken then die every day. It might be coincidence but it started happening after I left in a tubiworms cube for a day as a treat which none of them seemed keen on so I removed. The betta still looks lively and in fact has been attacking the neons but only when they got very weak and unable to swim out of range. The shop said that the betta and neons would co-exist in a community tank happily. We took sample water back to the shop and they said it was not good - I was changing water every 4 days or so and testing with one of those 6 in 1 kits which seemed to say things were ok - leaving new water to stand for 24 hrs or using tapsafe - and heating new water to 80F before adding. The shop has since advised to do a 10% water change every day - sadly too late for the neons, where have we gone wrong ? How can we stop the cycle of losing fish?

Thanks
Adam

ANSWER: Hi Adam,

I'd say it was Chloramine poisoning.

In tap water, we have Chlorine.  A chemical most people are familiar with.  But, nowdays, we also have Chloramine.  Chloramine does not disappear after 24 hours, in fact, it can take five to seven days to kill a fish if it's in the tank and the only way to elimate it is through using a dechlorinator product which treats for both chemicals and/or to use a distilled or filtered water which comes from a filter station.  I recommend the latter.

Water quality tests that come back poorly make large statements about the filtration in the unit.  

I've looked up the moon pod.  The filter looks okay.

Never leave food in the tank at all...even for a night.  Overnight, meat can rot.  We all know not to leave it on the counter for more than 20 minutes.  Imagine it in water...warm water.  Yuck.  

Neons are very touchy fish. :)  I recommend using the filter station water instead of tap water from here forward.  They will do very well with it.  Mine do fantastic with it.

The heat in the tank is too high.  The betta is a fish which likes 70 F degrees and tetra no higher than 72 degrees F.  My guess is they died from a combination of overheating (which reduces their ability to oxygenize the water) and chloramine (another de-oxygenizing situation) and probably some ammonia/nitrates/nitrites (food at the bottom).

This is all very sad, but it's par for the course, so don't take it to heart, please.  As a new aquarist, this is bound to happen and it might happen a few times in a row before you get the hang of things.

For now, get the water changed and siphon the gravel if you can. :)

Change your filter media.

Add new fish in a month.  

I hope this helps and Adam, I'm so sorry for your losses. :( But, again, don't beat yourself up about it.  It's all part of fish-keeping in the beginning.

Renee

---------- FOLLOW-UP ----------

QUESTION: Many thanks Renee, I am grateful for such a quick reply, ... can you tell me why I need to change the filter media, is it badly contaminated now because I left the tubiworms in ?

Answer
Adam,

Yes.  It's not badly contaminated, but filter media typically comes with brand new, activated charcoal and it should be replaced monthly anyway.  #1, it's probably time to replace it, and #2, yes, the tubeiworms dissolved in the tank sprouting very bad matter to the filter.  If we want to clear up the water quality, that's the first place we need to go to successfully do so. :)

Renee