sounds a bit anal but id almost be inclined to leave a cam running for 24hrs recording tank to see how the 2 interact throughout the day... fh's are a sod! im not thinking you dont know this for a sec just saying cos its not outwardly aggressive when your about doesn't mean he isn't at a certain point of the day, late in the night or early in the morn or something....
and 2xfx5s can handle bio load of a 18" lei and a fh just fin....
READ THE OP!!! jeehz....
i kept so many aro, it doesn't matter if its a silver, ozzie or asian. aro they requires good filtration and clean water, some people that kept asian aro without using a sump always ask me for help on how to treat their sick aro and improve their filtration.
First off, a sump isn't going to help lower nitrates. All it will do for the OP's tank is add more water into circulation and possibly increase surface agitation. Secondly, the OP's ammonia and nitrite levels are fine, meaning that there is sufficient levels of Nitrosomonas and Nitrobacter living in the biomedia of his two fx5s. Thirdly, in your original post you ask the OP to, "add more ceramic rings or bio-loads," while adding more ceramic rings is not a bad idea, adding more bioload certainly contradicts your argument for him to get a sump in the first place. If indeed his 2 fx5s are already insufficient for his current bioload (an 18" lei and handsized KKP, which i believe is light for a 240), then how would adding more bioload be a good idea? Lastly, although getting a sump should be on the OP's to do list, it is not going to immediately fix his problem.
Yes, I agree. Leichardti are very sensitive to water conditions, and adding a sump along with an RO system, autowater changer, UV sterilizer, etc would increase its longevity.