Hi all I have a fresh water tropical fish tank 165 litres for 10 years this July. All good until about 4 to 5 weeks ago. My ammonia was high, so did the usual daily water change and still no luck. Visited Maidenhead Aquatics with a confirmed water sample so my test kit was correct, and purchased Arka MICROBE-LIFT Nite-Out II STARTER Bacteria 473 ml x 2 bottles. Still high ammonia, then contacted them again and was old to purchase the Aqua Bomb. Still high ammonia. My fish are alive and a clear water. I am at a lost as to why this is continually causing problems and no matter what I’m advised it’s not working.
It takes time for bacteria levels to build back up and deal with ammonia spikes and you need to establish what the underlying cause was and deal with that, too. How often do you normally do a partial water change on the tank and how much each time? If it's been too little, over time the water will have acidified and used up all of the carbonates which will have cause the beneficial bacteria to die off - other symptoms of this (old tank syndrome) are a low pH and high nitrates. There's an article here on how to deal with ammonia spikes and the potential, following nitrite spike. https://www.fishkeeping.co.uk/articles ... ammonia-nitrite-spike.htm