Arowana racing?

Question

I have 2 Silver Arowana in my 75 gallon tank. Having read a previous article about arowana jumping, I need help in Arowana behavior. I know what is legal and not so please give me educated answers. I have done extensive reading up on them, but I cannot find any articles on thier particular behavior patterns. My bigger one is almost a foot long now, and prefers to eat Rosies. The smaller one is about eight inches long, and prefers crickets. There are two decent sized oscars in there with them, an Irian Jaya Tiger barb, 2 7 inch Irid sharks, one good sized lavendar Gourami, male, and an assortment of pleco's and cat's for cleaning. The bigger one looks like he is having speed races back and forth in the aquarium, and the smaller one looks sick. He will move around, but sometimes will sit dormant at the top. Ammonia level reading of .2 and nitrite at .3. I cannot seem to get it to zero. Advice? Please be very specific.

Filtration on the system is a 110 gallon Aqua Clear Filter, it supports a packet of bio max with activated carbon on top of a sponge. Also has an air stone powered by a level 2 pump. I am considering returning the Irids because they are very jittery, though the Oscars pollute more. She really likes to coloration on the Oscars so I think we have to keep them. The Arow's still don't seem to want to eat much, but love having thier sprinting races still. I am considering adding on a 40 gph filtration at the other end.

Answer 1

It looks to me like your bacteria can't keep up with the fish waste production. That's quite a collection of heavy-feeding fish in a relatively small tank for the number and species you've got and the problem will only get worse as they grow.

The smaller arowana is probably feeling the effects of the high ammonia and nitrite which is why it acts sick. The other arowana's racing around may also be caused by these, but it's not to the point of lethargy yet. Eventually, the other fish are going to start feeling the effects as well.

The simplest solution would be to reduce the number of fish in the tank - either by adding another tank and splitting the fish up, or taking some back to the store. Also, be sure you aren't overfeeding, and increase the frequency of your water changes to reduce the ammonia and nitrite.

Some other options would be to add additional filtration (cannister or wet/dry filter) to increase the surface area available for bacteria to colonize, or to add a sump to increase the water volume. Neither of these would be a long-term solution, though. Your fish are going to outgrow that tank.

Answer 2

Its normal for arowanas to dash from one side of the tank to another. Thats why arowanas are more suited in large areas such as ponds (at the right temperature) where they can swim. Try adding a powerhead to create a strong current that the arowana cxan swim against.

Looking at your fish list, it might be too much a of a load for just a 75 gallon tank. That might be the reason why your ammonia and nitrate level are above 0 (too much of a bioload for your tank to handle).

Answer 3

My arowana swam back and forth too. I would look at the other fish in the aquarium. If you have several fish acting weird, then you might have a disease in your tank.