New to owning fish - Please Help

[rossnorman1]

I have recently bought a 90L tank. within this tank I had 6 mountain Minnows,4 Danios and 2 shrimp.

Sadly within the last week this has dropped to 1 Danio and 2 shrimp.

I am lost! I don't understand what is happening to them!

The water is clean, the tank is well oxygenated. the tank is well planted.


I will try and explain it all.

After the first Minnow died I decided to clean the tank, I did a 50% water change. All was good and back to normal for like a day, but during the next few days the minnows died one by one until it was just the danios and shrimp. A few days had passed and the Danios looked all happy and looked healthy, I just thought maybe there was a virus that only effected the minnows.

Sadly though a Danio then died which ruled out a virus only effecting the minnows. I then performed a total water change a day or two passed and the fish where fine. However more Danios died, I am now left with one Danio!

After a few conversations with people it was then suggested I might of over fed them? I was feeding them a pinch twice a day, I then brought this down to once every other night.

Even though the tank is clean, I'm feeding them less they still don't seem to survive.

During yesterday and today there was one Danio I could I could tell wasn't well, he spent a lot of time yesterday hiding under the bridge then today he started to go pale, wasn't moving apart from the odd movement and you could see his mouth move.

is there any advice out there please? I don't know if there is something I did wrong?

Any advice/ help will be extremely helpful please.

 

[NickAu]

Is the tank cycled?
Has it got a heater?
What is the water temp?
How long has the tank been set up?
What sort of filter has it got?
How often do you change water?
How much do you change?

 

[Colin_T]

Hi and welcome to the forum

If the aquarium has been running for less than 1 month you probably have ammonia problems caused by fish food and waste breaking down in the water, and a filter that has no beneficial bacteria to convert the ammonia into nitrite and nitrate.

Any new aquarium is simply a container of water with fish. When you put fish or fish food in the water they produce ammonia. Over a period of 2-4 weeks, the filters develop a colony of good bacteria that eat the ammonia and convert it into nitrite. A couple of weeks after that happens and you get more good bacteria that eat nitrite and convert it into nitrate. When the filter has all these good bacteria living happily, the filter is considered cycled or established.

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Until the filters have these beneficial bacteria, the fish will be prone to dying due to ammonia and nitrite in the water. To help prevent the fish from dying you should only feed the fish a very small amount once every couple of days, and do a 75% water change and complete gravel clean each day until the filters have established. To clean the gravel you use a gravel cleaner like the one in the following link.
https://www.about-goldfish.com/aquarium-cleaning.html

When you remove water from the tank you either scoop it out with a container or syphon it out with a hose. The gravel cleaner allows you to syphon water out and while the water is draining out you push the gravel cleaner tube into the substrate and lift it up. The gravel gets circulated in the big tube and drops back down while the gunk gets drawn up and out with some of the water.

Make sure any new water is free of chlorine/ chloramine before it is added to the aquarium. The easiest way to do this is to get a couple of new buckets that have never been used for anything. Use a permanent marker to write "FISH ONLY" on the buckets and keep them specifically for the fish. You fill one bucket with tapwater and add a dechlorinator/ water conditioner to the bucket of water. Then stir it up or aerate it for about 30 minutes (or longer if possible). While the bucket of water is aerating you drain and gravel clean the tank and tip the dirty water on the garden/ lawn. Then refill the tank with the aerated dechlorinated water.

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As for feeding, only use a very small amount of food once every couple of days. 1 or 2 flakes crumbled up would be ample for a danio. And don't worry about the fish starving. Fish take their body temperature from the surrounding water, so any food they eat goes into growing and movement. And at this stage the less food going into the tank, the better it will be for the fish, because there is no filter bacteria to break down the ammonia.

If you get an ammonia, nitrite & pH test kit from the local petshop you will be able to monitor these levels as the filter develops. If you can't afford the test kits then take a glass full of tank water to the petshop and ask them if they can test it for ammonia, nitrite & pH. Then write the results down and post them here.

if you do buy test kits try to get liquid test kits rather than paper strips, and check the expiry date on the packaging. Test kits can go off if kept in warm areas and also from just sitting on a shelf for too long.

You only need a basic ammonia (NH3/4), and nitrite (NO2) test kits and a basic pH test kit that uses Bromothymol Blue as the indicator solution.

 

[IHaveADogToo]

I'm almost wondering if this might be some sort of chemical contamination. When you clean the tank, are you using any chemicals or cleaning products? When you change the water, are you using a fresh bucket that has never been used for chemicals, or are you using the same bucket you mop your floors with? Also, what kind of water conditioner are you using, and what does your water change process look like?