Motoro sting rays

[koi]

Hi I was at the LFS the other day and I seen some motoro sting rays for sale I was going to buy them for my 120g arowana tank they were small only around a 3-5 inches long.But before buying them I thought I would check what other people had to say about them!And also would they bother my arowanas(Silver Arowanas) they are still juviniles only around 1' 3'' or the other way would the arowanas bother the stingrays?

Thanks

Justin

[deepRED]

Stingrays and arowana are a classic combination in Asia. Temperment wise, they won't bother each other. The issue lies in the size of your tank. Motoros get to be very large and a 120 will not be big enough for them.
Another thing is that stingrays require very good water quality, meaning low dissolved organics and ultimately low nitrates. They will not be able to tolerate poor water quality that an arowana would.
In your size of a tank it will be near impossible to keep the water quality up once the fish get larger, since both are messy and heavy feeders.
For success you would need a much larger, extremely well filtered setup, at least 2-3 times the size of your current tank. Utimately the larger the better.
Not saying that it can't be done or that people don't do it; I've seen an almost 4 foot long silver arowana in a 180 gallon tank. The arowana was alive, but was battling different defects due to poor water quality, not exactly ideal conditions.
As for buying smaller stingrays, I would stay away from it. Rays with a disc diameter of under 3"(tea cups) tend to acclimate very poorly and are notoriously hard to keep. For a first timer I wouldn't recommend it. If you do decide you can properly provide a home for one of these creatures I would start with at a ray that's at least 4-5" in disc diameter.
The best setup would be an indoor pond, if you had the space for it.

Just my two cents.