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Tropical Trav 04-29-2013 11:13 AM

Neon Tetras are killing each other!
I had 3 small clown loaches in my 29 gallon tank. I added 11 Neon Tetras and the Loaches killed 3 in 24 hours. I returned the Loaches and got 2 new Neons for a total of 10. The 10 Neons are now fighting with each other and 5 have been killed. There are at least 2 really aggressive ones. One is really fat and bigger than the rest. Any ideas why this is happening? I keep reading i need to add more but I had 10. That should've been plenty right? My tank is cycling, but i doubt this has anything to do with it.

Byron 04-29-2013 01:40 PM

Cycling does indeed have to do with it, as I'll explain.

Shoaling fish like all tetra need to be in a group, as you clearly know. Part of the reason for this is the hierarchy the fish will establish within the group. This manifests itself differently depending upon the species, but it is an inherent need of the species. When the fish are settled, and free of stress, there will usually be no significant physical damage with most species [some are different, like Serpae Tetra who will fin nip regardless]. But when the fish is under stress, this changes, and usually for the worst.

Ammonia or nitrite above zero is very stressful. The higher either level is, the more stress. There is also internal damage being done, and this adds more stress. Keeping the fish in too small a group can cause this too, as can too small a tank space, just so you know and to complete the picture.

Fish have few ways of dealing with stress. Sometimes they become weak and waste away, refusing to eat. But more often they take the opposite approach, and increase aggression. It is their only way of fighting back their frustration.

I certainly wouldn't add more fish until this settles down. Meanwhile, make sure ammonia and nitrite are at zero by doing daily water changes using a conditioner that detoxifies both, such as Prime or Ultimate. Are there live plants? Not only do neons and most tetra need the shelter of plants, and floating plants especially; these also help with the cycling.


Tropical Trav 04-29-2013 01:46 PM

Thanks Byron. I have been doing about 20% water changes every day and my ammonia is at 0.25 ppm. Nitrite is 0. I do have live plants. About 12 of them. Only one floater, a water sprite. I have a couple hornwart which supply plenty of hiding also, plus I have a few decorations perfect for hiding. I will just keep the fish i have in there until it is finished cycling i guess. My worry is they will kill each other and then i will not have any fish to continue cycling.

ZivaD 04-29-2013 02:18 PM

FWIW - the clown loaches likely did not killing your neons - they are more likely to be consuming the neons after they have succumbed (to the toxic water conditions).
Neons are not hardy fish, so adding them while cycling the tank is really just flushing your $$$ down the toilet. If possible, I would suggest returning all the fish and proceeding with a fishless cycle - then stocking your tank.

Tropical Trav 04-29-2013 02:42 PM

I do not know how to do a fishless cycle. I will have to read up

Tropical Trav 04-29-2013 02:47 PM

Where can I buy Ammonia? Or is there a product i can buy from the pet store?

Byron 04-29-2013 02:57 PM


Originally Posted by Tropical Trav (Post 1915802)
Where can I buy Ammonia? Or is there a product i can buy from the pet store?

No, please stop here. You do not want to change horses in midstream.:shock:

While it is true about the cycling, it is occurring or the fish would all be dead not from aggression but sheer poisoning by ammonia and nitrite. Let's continue with what is started, and build on that when it is settled.

Aside from this, with live plants...and the floating you mentioned are ideal for is possible to "cycle" without affecting the first fish. I've set up dozens of tanks from scratch with fish in them on day one and never had "cycling" issues just by using live plants.

We'll have to go into more detail on what you actually did from day 1 to see where things went wrong. I assume the clown loaches are gone now?


Tropical Trav 04-29-2013 03:01 PM

Yes the loaches have been gone since 24 hours after the first Neon stocking. The Neons have been alone for 5 days. Please advise how I continue to cycle with these fish, as I would prefer this method.

Byron 04-29-2013 03:06 PM


Originally Posted by Tropical Trav (Post 1915922)
Yes the loaches have been gone since 24 hours after the first Neon stocking. The Neons have been alone for 5 days. Please advise how I continue to cycle with these fish, as I would prefer this method.

Daily partial water changes of half the tank. Use a good conditioner, in this situation one that detoxifies ammonia and nitrite is wise. Prime does this, as does Ultimate. Do some vacuuming of the substrate in open areas when you water change.

This should get things stabilized with the plants. What to do with the mean fish I'm not sure. I suppose let nature take its course.:|


Tropical Trav 04-29-2013 03:11 PM

I will get some Prime. Do I add it in with the water in the bucket before i put it into the tank or do I just change 15 gallons and then put enough Prime for 29 gallons? After the first use, I would assume in the bucket (new water) only. Is this correct? Also, after "nature takes its course", what do I do to keep the ammonia up to complete the cycle?( I want glass catfish, cherry barbs and Neon Tetras by the way). Stock new fish?

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