Water quality newish tank

Question
I have two fish tanks.  1 small 7.5 gallon tank which has been up and running for months and a newish one 47 gallons that has been up an running about 4.5 weeks.  I had quite a few fish in my smaller tank which once established I was going to transfer to my large tank.  On the second week of my new tank setup my filter in my old tank packed up.  I panicked and transferred my fish to the new tank.  I have just tested the water in my new tank as I have recently lost a couple of small plecs and a rainbow shark.  The results are as follows

Amonia  7.3
Nitrate 5-7
Nitrite 0.1-0.3
PH  5.5 - 6.0

The day before yesterday I did a 33% water change removed all the waste, added a new carbon filter and added Nurtafin Cycle.

Please advise on what you feel on what else I should be doing.

Many thanks
Jon

Answer
Hi Jon,
~You did the right course of action with a water change and the addition of "Cycle". Your 47 gallon has simply gone through the usual ammonia spike most new aquariums encounter. However this is very serious and high ammonia is very toxic to your fish.  You may have added too many fish at one time from your 7.5 gallon. And this likely caused the ammonia spike. You need a food source for a new aquarium to cycle which means fish but you can't add a whole big group at one time. But even if you add only 6-7 you will still most certainly get an ammonia spike. This is why daily testing of the water for ammonia is so crucial and if the reading is out of the safe bounds you must do a 30-50% water change right away.

You will have a ammonia and nitrite spike for several days until your bacteria get established and bring both those levels down which is when your nitrates begin building up as the end waste product of the cycle. Nitrate is best removed by your frequent warer changes. A cycling aquarium can take about 4-6 weeks to get established with a thriving beneficial bacterial colony.

Your best bet is to try to keep only about 5-6 fish in that aquarium. Feed them VERY lightly. Once a day.
Test the ammonia and nitrite+ nitrate everyday. If ammonia/nitrite are out of safe bounds--do a 30-50% water change. Continue this for at least a couple of weeks and when your ammonia and nitrite have dropped to zero and nitrate is on the rise, your aquarium has cycled! Now you can give your fish the space and living area they deserve!
;-) Just be sure to test the water after each new addition to be sure and not get a spike in ammonia again.

In the meantime you can use ammonia neutralizing/removing water conditioners such as Amquel or Prime for your water changes to help reduce the effects of toxic ammonia. Keep in mind, however some ammonia neutralizers can give false readings on ammonia tests. Fortunately most products list which test kits are compatible.

I really hope this helps! If you have anymore questions, feel free to email me as always...

You are doing everything right. Just continue daily testing and water changes and your aquarium will establish with time.

Best wishes and happy fishkeeping!
Karen~