Hi everyone. (I will use UKgals instead of USgals although I'm familiar with the latter)

I have a young 5" Oscar temporarly in a 26gal bow. Thanks to your advice (and from the guys at fishlore.com) I managed to handle what seemed a stress overload for Moon (the Oscar's name.

A 72"Lx18"Wx26"H tank will be the final destination, that means 120g Today I installed a HOB (AquaClear 110, formerly 500) in the 26g bow to cultivate bacteria in its media (without the charcoal, I intend to add it when transfered to the final tank).

I purchased the bare tank (it's at the LFS) housing some goldfish (got a good deal for it, it ended up being a bit taller than they needed) and arranged for them to transport it when I'm ready.

I decided to go with two AquaClear 110 since these are designed to house ceramic cylinders for the bio-filtering, and I intend to rinse the sponge and replace charcoal bags in alternated ways.

I will use sand substrate (river sand, carefully rinsed) since planted tanks work better in my experience (keeping nitrates down). Even if I end with floating plants only and frequent uprooting (some guys report their Oscars ignore plants, so I'm hopeful).

Since I live in the Caribbean, in low altitude -near sea level-, temps remain quite steady all year long and through day/night cycle, tank's water temps around 26C-29C (79-84F).

I haven't solved the canopies/lighting yet. I might have to order them online. If you have ideas or suggestions, please let me know, so I learn from you. I'm newby for Oscars (Moon is my first one).

I intend to use a custom made, reinforced, metal structure of 74"Lx20"Wx40"H (will meet the mechanical/structure engineer Monday morning), with 1" or 3/4" plywood on top, and rest the tank in styrofoam. To protect the floor tiles, I might use styrofoam there too.

This tank will be in my house's office, so aesthetics are not a big priority right now. I am guessing around 1600lbs+ in total weight load.

Earthquakes, although not rare, are usually very mild around here.

Thank you. Your ideas are very welcomed.
Pepe
Santo Domingo

Sounds like you have things really well planned out. I have got various fake plants in my tank and my Oscars pay absolutely no attention to them whatsoever so not all Oscars destroy plants.

I'm glad you're going with sand, you will love it, it's far easier to manage than gravel so you will keep your tank cleaner. Anyway, looking forward to seeing some photos. I am giving their site a facelift soon and I hope to give each member at the chance to create their own gallery where they can have photos.

I'll keep everybody posted

your setup seems fine imo. the only change i would make is only on the filtration. aquaclear hob filters are probably the best but from what ive read and experienced you should go for 10 times your total water volume in gph. so for a 120 gallon tank you should have a flow rate of 1200 gph(imp) total. the ac 110 have a max flow rate of 500 gph(us) so in your case i would use three ac 110s.

on my set up which is only a little bigger than yours i have 3 ac 100s and a 900 gph sump and i have no probs at all with ammonia and nitrites.

also i would forgo the carbon and maybe use a fine filter pad instead to help with water polishing. carbon media is not needed unless you are removing meds and such from your system

Thanks for the info on filtering. Would It be wise to add a sump filter designed for 75gal instead of a third HOB? (There's one at good price at the LFS). Would that make sense? I know it would be cheaper to go with another AquaClear 110, just wondering.

Expecting the tank home by Saturday

Pepe

Plants growing on bogwood tend to be ignored by oscars, even the ones that like to dig plants up from the substrate

On the subject of substrates me and OFL disagree on the best. I prefer gravel. It gives them something to did in and move around. Sand isnt the easiest thing to keep clean, i have to syphon the fish waste from my discus tank twice a week. A couple days after doing one of these cleans waste starts to show.

With gravel, If you set up a undergravel filter but with an outlet from a cannister filter pushing water down the uplift tube you dont have to gravel clean except a quick scoop over for large waste. Much easier than sand.

personally i would use a sump over another hob filter. they provide the best biological filtration and also give you the opportunity to hide heater in them.