Had an interesting development after I cleaned my pond.. As the pond water stank, I had to practically clear the entire pond and wash all the filters, chambers, etc.. What this meant was I had to ‘season’ new water for about a week before I can consider putting new kois in.
Anyway, I had 3 small plecostomus (only about 0.75 foot each) in the pond which I had to take out and the only place I could put them was in my arowana tank. Did not think that this would be a problem as these sucker fishes stay at the bottom and would not get in the way of my 2 foot red arowana. I was even worried that my arowana would not take too kindly to these new additions! Anyway, I was pleasantly surprised that they got along fine in the tank! …
That was what I thought anyway! I thought nothing of it until about 2am in the morning as I was going to bed. I always pass by my arowana tank when I goto bed and saw that my arowana was practically being chased around the tank by 2 of the plecostomus. What I noticed was that they were trying to ‘latch’ on to the arowana’s body to sucker on it! Healthy fishes always have a layer of protective mucoprotein slime coating that covers it’s entire body and the these jokers were trying to get to it! And to think that I was scared that they would get whacked by my arowana! 
My poor arowana must have been trying to avoid them for hours as it was really stressed and gasping. So what did I do? At 2am in the morning, I had to remove these jokers from my arowana tank. Took me about 20 minutes to catch them with a net and ofcourse got myself wet doing that. So instead of going to bed, I had to take another shower after that saga! Man!.. as if I had not had enough excitement after cleaning my pond!
Ok ok what is the moral of the story?
Do not assume that all the tank mates will get along with your arowana. Always observe to see what happens! This is the first time I am seeing a plecostomus giving my arowana a hard time. And mind you.. this was just a little fish and I would have expected my arowana to really whack it once to warned it BUT IT DIDN’T! Don’t ask me why because my arowana has always been aggressive towards other tank mates but not this particular plecostomus! (I have had others before in the same tank and none of them ever bothered my arowana. FYI, I have taken out the 2 that was trying to ‘suck’ my arowana and left the bigger one in there. This last one does not bother my arowana at all…
I guess fishes are like people eh.. some of us get along but some dun! 
Steven
hi steven,
kindly warn all arowana lovers not to trust the plecostomus. They look kind but they attack when the fish passes by. One got my Jardini away thinking that the plecostomus will just suck all the dirt. I also noticed it when I tried to put 2 young plecostomus(4-5 inches long) in my goldfish tank. They simply follow the fish routines and slowly suck the scales.
you can also mail me at mark_makiramdam@yahoo.com
marky
Mark,
I have seen many plecostomus that gets on extremely well with arowanas but some just don’t unfortunately.. Keyword is observe! observe! observe!
You are right to a certain extent. As I said, you just have to observe when you have one of these sucker fishes in the tank… I think it is all about chemistry!
Steven
May I breed Flower Horn And Arowana
Ofcourse you can!
But your success with flower horn will definitely be much much much more successful.. Arowanas are not easy to breed and need a conducive environment..
I have one Silver Arowamer and on asian Arowaner in my pond.
Will they beable to stay there over the winter time?
I filter my pond 4 hours aday with Lava gravel and peedmoss.
and the seeme to like it. They hyde out in th rocks most of the Day time but also come out at times.
I live in Grass Valley California.
Heinz
Heinz,
How old are your arowanas? How cold can the winter be in CA? Why I ask is you will have to be mindful as arowanas are from warm climates and it could be more susceptible to diseases if the temp drops too much. You might need to warn the temperature up a bit..
All the best..
Steven
I have a gold arowana right now in my tank and I was wondering if I can put another arowana? or another fish what can I put with my arowana??
Paul,
If they have not grown up together, you should not add another arowana in it as they will fight and can be fatal. As for suitable tank mates, they are too many… example are tigers, stingrays, etc..
Steven
i have kept an arowana and a flowerhorn in the same tank………bt the tank is not so big…but moderate,…is it secure to keep……!!!?????
Rohan,
My only advise is… you need to change to a bigger tank.
Steven
Hi steven, is it ok to have frontosas as tankmates to my rtg? right now, i have 2 super red severums and 4 silver dollars with my rtg all in a 225 gal tank. I’m really eager to put a few blue zaire fronts with them. Hope you can help me on this. thanks.
Jong,
Those tank mates are fine… How big is your tank though? Make sure it’s big enough to accomodate so many ok… Can get a bit crowded in there which is not advisable..
Steven