[Newbie] Fish keeps dying

[Nifster]

Hi, let me give a brief intro about my set-up first.

I'm a newbie to the hobby, got my first tank 7 weeks ago. The tank is 22.5cm by 14.5 cm by 18cm, OceanFree front curved tank. When I bought it, it included a 7W AquaZonic PL tube lamp with a Classica Crystal 1 (output 120L to 150L) hang on filter and some OceanFree anti-chlorine. I got a sponge to cover the inlet since I planned to keep shrimps. I bought some small artificial rocks and a windelov fern as well as some java moss.

Did the fish-in cycling with some neon tetras and 4-5 weeks later added around 10 sakura shrimps after confirming the cycle to be done. Unfortunately, 7 died the next day, and the population dwindled until there were none left the next week. Having spent so much on the sakura shrimps, I thought I would give up on the shrimps and added more neon tetras. Few of them survived, I'm left with 3 neon tetras. Few days later, bought an oto, which is still alive and well(kind of fat too). Decided since maybe I can try again, and added 6 Celestial Pearl Danios. All of them promptly died the next day. Getting frustrated, I did a large water change, and tested the water to confirm no ammonia or nitrite. Bought 6 more Celestial Pearl Danios and again, all of them died the next day. I do condition any fauna before adding to the tank for 1-2 hours by slowly adding my aquarium water to the container.

Tl;dr, 10 sakura shrimps lost, 3 neon tetras lost, 12 Celestial Pearl Danios lost. Help?
Pics of my aquarium will be uploaded if needed.

[allblacks]

Probably you need to also put in liquid bacteria to jump start your tank.

[Nifster]

Probably you need to also put in liquid bacteria to jump start your tank.

Sorry, do you mean that I should add in liquid bacteria to jump start the tank cycling process? 'Cos I already indicated that my tank has cycled. Unless you're implying something else. If so, please elaborate.

[VSGenesis]

Hi there, before you try or add anything, can we have a look at the tank please. Don't spend on any other chemicals or fauna. Your tank is about 6 litres? Less than 2 gallons. 1.5 gallons to be exact. Pretty small tank. You cannot overload it with fauna. Not accurate but just a rule of thumb is 1inch of fish per gallon. So, you can see you might have overloaded the tank. For that size, base on the Celestial Pearl Danio which grows up to approximately 21mm, you can probably put 2 or max 3 Celestial Pearl Danio.

Here's a link to know more about this cute and lovely fish. They love to tango. http://www.seriouslyfish.com/species...-margaritatus/

[Cyberkinetic]

What type/brand of testers you got for testing ammonia and nitrite? Seems that not all brands and types of testers are made to test parameters accurately from what I've been reading... Maybe you can test for PH as well..