Need advice on keeping Arowanas

[anthoni]

hi

I am relieved that the RTG has eaten 3 fishers yesterday. I had changed 20% of water too.

I had cycled the water for a week before putting the arowana.

For informations, may I know what is the estimate age for a 5" arowana and how to differentiate the gender. (I did not ask when I purchased it) What is the likely signs that I must look out if the arowana is not in its healthly condition.


Tks

[vinz]

Even the breeders can't sex the arowanas accurately. There have some vague signs, but until an arowana starts breeding, they can never confirm the gender.

Can't help you about the age.

As for health, it's the usual signs. Look out for listlessness, poor appetite, etc. There will be times of the day that the fish will just rest at the bottom of the tank, but most will start moving once they notice people approaching the tank. Even if they don't move (once they are familiar with you) you should still notice that they have become more alert and start to watch you.

[anthoni]

It's possible that the shop does not feed the fish much, so on the first day in your tank, it gorged itself.

The stomach of the fish is not very big. A 5 inch arowana, probably only has a stomach slightly larger than a Singapore 50 cents coin (thicker of course). So how much do you think it can eat at one go?

Something interesting for you to know... the arowana is a mouth brooder. I.e. the female lays the eggs, the male fertilises the eggs and then scoops them into his mouth. He will hodl the eggs in his mouth until they hatch. The fries will live in the protection of it's mouth for a number of weeks. It cannot eat during that time.

So don't worry too much that it will starve to death quicky if your arowana stops eating completely. BUT, you should still it as a sign that it's not well and investigate.

hi

The water has turn bit greenish and I do not know what is the cause for it. I dare not add available cure for it as I do not have expereinces with arowana.

Your soonest solution to it is greatly appreciated.

Tks

[anthoni]

Oh... just occurred to me. Did you let the tank and filter mature and cycle properly before putting the arowana in? If you did not, watch out for a ammonia peak, followed by a nitrite peak before your tank stablises. In that time, your arowana could well be killed by the ammonia or nitrite peak. You had fishes before, so I hope you didn't forget.

hi

The water has turned greenish and I dare not add other forms of cure to get rid of it. Is there any safer ways to clear it as I have no experiences with arowana tank.

Tks

[mordrake]

greenwater is usually triggered by ammonia with high light.
what's your filtration and lights (wattage, light duration) like?

[anthoni]

hi

I am using model:Ehiem2028 for filtration and T5 light. However, the lighting is on only around an hour per day.

I change the 25% of water around every 5 days. This is my second week keeping the RTG. Is this the correct way ?

What is the best way to clear it now; I appreciate for your kind assistance.

Cheers

[mordrake]

what biomedia is in the canister? is your tank near a window? move it away if it is or use something to block the sunlight from hitting your tank.
being the 2nd week, the tank is not fully cycled yet. so there would be ammonia present in the water.
you can just let things be and keep up with the weekly water change.
in another couple of weeks when the filtration matures, the GW will go away when ammonia drops to almost zero.
a faster way would be to get a UV sterilizer.

[vinz]

Is the tank exposed to direct sunlight? That is a surefire way to get green water.

What media do you have in your filter?

Green water is microscopic algae floating in the water. Light and ammonia/ammonium/nitrate feeds them.

It may be that your tank has not completed cycling, so the ammonia/ammonium or nitrate peak may have triggered the green water. What you need to do is kill off the algae by depriving it of light and give the bacteria colony in the filter a chance to grow and consume the excess ammonia/ammonium/nitrate.

A large water change is usually prescribed for green water, followed by a complete blackout. I do not recommend large water changes in Singapore anymore after personal experience. Large water changes with our tap water could kill off the bacteria in the filter (or at least that's what I suspect).

Turn off the lights for now. Do your normal 25% water change. Then blackout the tank for 3 days: Wrap all sides tank in opaque dark paper or use cardboard. Leave no gaps. For the top, put a cloth/towel over it (cloth can breathe and allow exchange of gases).

If you have feeder fish in the tank, remove them. Stop feeding during the blackout period. This is to remove sources of ammonia/ammonium.

After the 3rd day, remove the blackout and do another water change.

Are you aerating the tank? If not, you should make sure that you can keep the oxygen in the tank at life sustaining levels with an aerator or making sure the water surface moves (use the filter outlet).

Lastly, work slowly when you are blacking out the tank. You don't want to frighten the RTG.

[anthoni]

hi Morning

My RTG has grown well and I will probably purchase a bigger tank within the next 3 months. I appreciate very much for the past advise.

Meanwhile, I would like to enquire if there is any different rearing where temperature is involved. Will the colour change or what will be the outcome if let say we have cold temperature for it.


Tks

[Madmax]

Room temperature is good enough. There is no need to have heater or chiller in SG.

[anthoni]

Hi

I am wondering if it will have any effect if the RTG is kept in the air-con room (office); where the air-con is on for 9 hours daily?

Cheers
Anthoni

[Madmax]

In that case, a heater may be required. Temperature around 26-27 deg C should be good enough.

From my personal experience, a UV setup is a must to keep sickness away.

On the subject of keeping aros in office, have you considered how to perform water changes? Usually, the restroom is pretty far away.

[anthoni]

Hi

I appreciate very much for your informations.

Cheers

[anthoni]

helo

I am pretty busy lately; and my RTG is pretty fine. It has grown well and I will be having my 5 X 2 X 2.5 tank with sump next week. Can someone provide me advice if the UV is to be on 24/7 or just for a certain hours per day.

Thanks
Anthoni