What is healthy Fahaka behavior?

[Indeed]

So i work at my LFS and we had a fahaka 7-8" there for a few months and i picked him up. He was kept in one of the stores 75g
tanks, he was very active and extremely aggressive as well as very hungry all the time (and eating huge amounts). Well i moved
him to my 120g planted tank at home, and now he is very passive and wont eat more than a single clam (1/3-1/2 of what he ate
while at the store). He is also mellow and sits for long periods only to occasionally swim up and down the front panel. He has been
in the tank for about 4 days.

Is this normal? he was so much more active and glutinous at our stores smaller tank. what gives?
what is "normal" behaviour for a healthy puffer?

The tank specs as of today: Ph 7.6, ammonia 0, nitrate 30, nitirite 0*

filtration: home made 5g biofilter, 50w uv sterilizer, pag of purogen.

*after seeing the specs did a 40% water change with gravel vac, lots of detritus. this most likely will solve my nitrate issue.

[bertie 83]

Sounds like normal fahaka behaviour to me

[puffykid]

Also if you've only had him for 4 days then he may be still adjusting to you, puffers are unique in that they won't eat if they arent comfortable yet so don't be surprised if he hunger strikes for a bit. Just let him adjust in to his new living arrangements and he will probably perk up a bit, does he have a nice hidey hole to retreat to? That often helps them feel more safe and then more active, of course some fahaka's are just lazy and will just lounge around all day regardless of treatment. What you saw at the store may have been him trying to store energy up to keep himself healthy.

[scpion]

Btw, fahakas are one of those that will burrow quite often. And they do chew up plants. Good luck to your plants..

[RTR]

I've had 3 of them (separate tanks of course). All three behaved differently. One was hyperactive, always hungry, and dangerous. One was moderate on those things. The third was rather bashful. They could see at leas one other Fahaka. They are intelligent fish and have a broad range of "natural" behavior.

[Indeed]

Thanks for all the input, my fahaka is starting to relax and behave more like before. He is certainly less aggressive now, but as i recall it was about 3 weeks before he really acted like he was ruler of his domain in the store tank. So i am sure some cohabitants will disappear in the near future lol. As for the plants, they are high light fast growing plants and i am dosing excel, so even if he was a herbivore i think i would be alright lol. again thanks for all the input

[Pufferpunk]

Why risk the lives of his tank mates? Please remove them, unless you can be assured they won't be harmed.

[Indeed]

He killed 1 of 12 tank mates in the month he has been in. The tank-mate that died was slightly territorial and kinda had it coming. the 3 Siamese algae eaters, 7 Odessa barbs and 2 goldfish* stay away and he leaves them alone, seems to me the dense plants help. (*The goldfish have since been moved out, they were awesome duckweed exterminators though). All this to say he is pretty non-aggressive until food hits the water; if he were to start massacring his tank-mates i would move them out.

[RTR]

If the fish is not yet mature, you really cannot predict anything about what the personality will be at maturity.

[bertie 83]

If he does turn killer you will be unlikely to save any fish, he would likely strike at night murdering everything in 1 sitting. He may choose to kill nothing, unless they irritate him lol

[Pufferpunk]

You're keeping GF in a warm-water system?

[Nuclear_Glitter]

You're keeping GF in a warm-water system?

He said he removed them.

Also, OP, be sure to feed a wide variety of foods so he doesn't get a deficiency of some sort. Vitamins are also a great thing to consider.

[Indeed]

Yeah i moved the GF out, and i can't stress enough that they were just there to eat duckweed and they had been treated for disease before they became residents.

To be honest i don't care about his tank-mates they are just a clean-up and algae control crew. I am sure he will kill them sometime in the next 10+ years that
i plan on keeping this fish. they are not exactly rare fish either. call me mean but unless he totally massacres the tank in 1 night, if the occasional disappearance
happens they will be replaced.