Vanishing Neon Tetras

[Mostlydave]

I recently bought and resealed a 55 Gallon tank. I moved my 10 gallon tanks biological filter into the filter of the new tank hoping to get a cycling boost. I had the 55 stocked as follows:

8 neon tetras

7 ember tetras

6 x-ray pristellas

4 black skirt tetras

4 glo fish (zebra danio)

starting 2 days ago my neons started vanishing and now I'm down to 3 I've been testing my ammonia and it hasn't been above .25 Could the other fish I listed above be eating the neons? What are they dying from and what can I do to help them? I do have an empty 5 gallon tank that I kept to use as a quarantine but I'm thinking that's not going to help as it isn't cycled either. 3 of the neons went missing in between last night and today after work, could the other fish eat them that fast? I've looked all through the tank and filter and haven't found any trace of them. Help!!

 

[waterdrop]

Neons can be quite sensitive to changes. I often advise beginners to run their tank for another 6 months or longer -after- it is fully cycled before attempting a shoal of neons. Even when good technique is used and mature media is introduced to the new filter of a newly set up aquarium, the new situation must still be treated as a cycling situation and thus the whole time-period thing is starting over in a sense.

Now it is also possible that you may have had trouble from the black skirts. They can be quite mean in my experience and of course, as with most tetras, you are really asking for it when their shoal number gets below 6, as yours has. You really want them to be up around 8 or 10 to be sure they will be fully occupied with each other rather than thinking of terrorizing the other species in the tank.

Since you will still have some neons, it will now be important though to consider bringing their numbers back up. Tetras that get below a minimal shoaling number will think they are lost from the school and that they are going to die, they will stay at a constantly elevated stress level. If you end up with 5 neons still left, you could probabaly go a few months before adding to them but if you get down to 3 or 4 then it might be good to up them sooner.

~~waterdrop~~

 

[Mostlydave]

Thanks for the info, I'll try to add some more black skirts, they seem to only pick on each other, Is that ammonia level ok? how much water should I change and how often? I had been doing 6 gallons every other day but today I did 9 (3 gallon bucket) There's so much conflicting information about cycling and water changing that it's hard to decide what's best to do.

 

[waterdrop]

Your first and main focus during any fish-in cycling situation (what you are in) is simply to use your liquid-reagent test kits to make sure that your ammonia and nitrite(NO2) levels stay below 0.25ppm (or 0.30ppm if that is the first color of your kit) and you have to be a sometimes creative "detective" in figuring out what combination of size and frequency of water changes will both accomplish this as much as possible and will also work with the realities of your work/school schedule or whatever. Does that make sense?

The bacteria will take care of itself. It will slowly (usually over a month or two) build up until the filter can keep a pristine zero ppm ammonia, zero ppm nitrite(NO2) and thus the tank will be fully cycled. Meanwhile though, your job is to keep the fish alive and healthy by exposing them to the smallest amount of toxins possible. Ammonia and nitrite spiking into the 0.50 and above level is much, much more stressful to fish than water changes are (although it is still important for water changes to be done with good technique - rough temperature matching and use of a good conditioner such as Prime.)

It mostly just takes lots of patience and dedication!

~~waterdrop~~