My green aro is now starting to get itchy and has small white stringy slime coming off him. The water is fine nitrite, ammonia, nitrate and ph is all going smoothly now. I had been treating him for flukes because it glances itself of decor and scrathing itself with its fins but there hasnt been much improvement. Any advice? could it be something else here?

It could be the water, but since you've tested the water that's not the case. It could be ich also. You really should medically treat until you know exactly what you're dealing with. It could do more harm that good. Check your water again. I would also do some water changes to get the medication out. It may be causing him to lose his slime coat.

Good call Dan. I would also bump up the temp to about 82-86* and add aquarium salt. Put 1-2 tbs per 5 gal of water. If in fact he is loosing his slime coat that will help him get it back. Make sure that if you bump up the temp that you also increase the air. The warmer the water the less oxygen will be in the water so you will need to aireate (sp?) it more.

Ok I've put the aquarium salt in and added an airstone And it seems the slime has now disappeared
If it was ich wouldnt i be able to see spots? I have really got up close to observe him and see no visible signs of disease except for the slime.
The med i used was a water life product and is meant to be very mild and treatment is over five days which you add on 1,3,6,8,10th days because it meant to build up in strength not give the fish a big blast of med.

If it is ich, you can see the spots...However, i personally haven't seen an asian arowana with ich. Just use the salt and temperature method and you'll be fine..if it gets worse, then only use medications..

I would just use the salt and the temp as well. I'm fairly sure it's not Ick. Just remember to keep the water clean and remember salt doesn't evaporate so don't add more if your just topping off. Only add more salt if you do a water change. Sounds like your fish should be ok. Keep us posted and make sure to watch'em for changes.