Zebra Danios losing stripes occasionally & newbie questi

[Exar]

Hi there,

I recently purchased a 60Ltr Biorb, set it up as per instructions. During the first day when I had no fish in it I read everything I could on setting up an aquarium so I guess I am at educated newbie status

My first fish were 3 Zebra Danios as from what I had read they were hardy and good for new tanks during cycling.

The tank has been running now for 2 weeks with the fish. I've been feeding the fish Hikari Tropical Micro Pellets each morning (a small amount).
My water readings are:-

Ammonia : 0.25
Nitrite : 2
Nitrate : 30
[acronym:2c17ed04e4="power head or Measure of the concentration of hydrogen ions, depending on context"]PH[/acronym:2c17ed04e4] : 7.2
Temp : 26 degrees

Sometimes I have noticed the fish losing their stripes. Is this normal, should I be worried? It doesnt seem to last long around 5-10 minutes.

When would you recommend adding another fish? Should I wait until the nitrite level peaks and falls to 0?

I've been looking at the fish available and thinking of final stocking levels, here is what I have come up with :-

6 Zebra Danois
1 Samurai Fighting Fish
1 Red Tailed Black Shark
2-3 Guppies

Can you see any problem with this final stock level/compatability?

Having fun so far.

Exar

[Fishyfanatic]

The losing of the color could be from stress or is sometimes associated to lack of light. But if it's not first thing in the morning, it could be stress. Do extra water changes to get the Nitrite and Nitrate levels done and see if it improves.

I'd wait until the tank is cycled before adding more fish. The only potential problem I see in regards to compatibility is the guppies and Betta mix. I'd choose one of the two. And if you choose the Guppies, increase that number to about 6. Also, I'd nix the Black shark. Your tank is roughly 15 [acronym:7917f0e039="Gallon"]gal[/acronym:7917f0e039] and it would not suit well for that tank. I'd go with the 6 Zebra Danios and the 6 Guppies. That is still pushing it, but if you keep up with weekly water changes, you shouldn't have a problem. OR, you could just have 1 of the two, then a small school of bottom dwellers like Cory's.

Also, what test kit are you using?

WELCOME TO AQUARIUM ADVICE!

[QTOFFER]

Welcome to AA, Exar!

It seems as if you've already done alot of research about the nitrogen cycle. Check out our articles section for additional info.

Zebra danios are pretty hardy - if one chooses to cycle with fish, they are probably the best species to use. Just be sure to do frequent partial water changes to keep the ammonia and nitrite levels down. Thiss will slow down the cycling process slightly by reducing the available amount of ammonia for the bacteria, but it's necessary to keep the fish healthy. For the first few weeks, avoid disturbing the filter and the gravel - that's where the beneficial bacteria are setting up shop.

I wouldn't worry too much about the fish' stripes so long as they're swimming and otherwise behaving normally. Watch out for signs of ammonia/nitrite poisoning - lethargy and rapid gill movement - and be ready to do a partial water change if you notice them.

I would definitely wait until the ammonia and nitrite levels fall to 0 and stay there for a few days before adding any more fish.

The biorb looks really neat and I like the way it magnifies the fish while hiding all the equipment. However, it does have a serious design flaw - a very small water/air surface area:volume ratio. The number of fish that you can stock in a rectangular aquarium is largely based on the surface area of open water. This is important for efficient gas exchange ([acronym:9918baf242="Oxygen"]O2[/acronym:9918baf242] in, [acronym:9918baf242="Carbon dioxide"]CO2[/acronym:9918baf242] out). Fish and beneficial nitrifying bacteria need lots of oxygen, and will die if the tank's water surface is either too small, or not agitated enough. Higher water temps needed for most tropical fish compound the problem by reducing the solubility of oxygen.

In a 60L (15 [acronym:9918baf242="Gallon"]gal[/acronym:9918baf242]) rectangular tank, you can safely stock 37.5cm (15 in) of small fish. In the biorb, which likely has 1/2 the water/air surface area of a similarly sized standard tank, you probably should not stock more than 1/2 of this. Adding an airstone to keep the surface well agitated will help somewhat.

That said, the red tailed shark is definitely out.
The Samurai Fighting Fish (betta?) might attack fancy guppies - probably not a good idea to put both together. Bettas can breathe air from the surface.

I would keep either
6 danios
1 betta

or 5 danios
3 guppies

You might also be able to keep one or two small corydoras catfish for bottom cleanup. They too often surface for supplemental air. They are happier in larger groups, but you're kinda limited by the biorb.

[Exar]

Thanks for the great advice guys, it certainly gives me plenty to think about whilst my tank is cycling.

Firstly I am using the master test kit from Aquarium Pharmaceuticals Ltd.

The reason I bought the Biorb as opposed to a regular tank was that I thought my cats would not be able to jump on top of it. So far they have not managed to get onto it. It has a few disadvantages though, due to the curve of the bowl there is not much room at the bottom to place plants also getting the plants in place can be difficult as you need to work one handed.

To anyone thinking of purchasing a Biorb, my advice would be to only put a couple of litres of water into it and check for leaks around the bottom. The first one I got from the pet shop leaked, and of course I only noticed this after I had put 60 Ltrs of water into it.

The manufacturers advise against placing bottom feeders in the tank due to the roughness of the ceramic media used, they say it could damage their faces.

Thanks again for the advice and the welcome.

Exar