yesterday i was checking my jardini arowana isaw it has white spots on its body and the fins and some near the gills. how do i cure it . i have malachite green and methylene blue which one is affective against ich.

no it is a 40 gallon grow out only an arowana , gar and a rainbow shark. should i switch off the filter?
Turn temp up a few degrees (make sure tank is well aerated) and add some salt. All you need to do. Should clear up in a day or two. Don't bother with meds.
Water quality alone is not the only cause, since it is a parasite it had to come from somewhere. Ich often enters the aquarium on plants, driftwood, or even newly added fish. Poor water quality, however, does create an environment that is much more conducive to the growth of ich.No medications required. No medication is going to work in poor water conditions anyhow so that's what you need to take care of first. What are your ammonia/nitrite/nitrate levels? Since ICH is typically caused by poor water conditions, I recommend you do a large wc, bump temp up to 86, dose with non iodized salt (I believe it's 1tbs per 5 gallons), and gravel vac daily as the ICH can fall down to the substrate and thrive sometimes.
After that, I recommend not overstocking your tank and keeping a more appropriate wc schedule.![]()
Water quality alone is not the only cause, since it is a parasite it had to come from somewhere. Ich often enters the aquarium on plants, driftwood, or even newly added fish. Poor water quality, however, does create an environment that is much more conducive to the growth of ich.
The treatments that you have reccomended are perfect though.![]()
Since ICH is typically caused by poor water conditions