Getting a new figure 8, need some advice

[BumbleBee]

So almost a year ago, I used to have a figure 8 pufferfish. I only had him for a few months or so before he jumped through this tiny hole next to the filter and died. The figure 8 had 2 guppies as tank mates, and I assumed that would be ok since he was only a 1 inch long baby. He was healthy and eating a ton before he jumped, and the guppies never bothered him. I did plenty of research on the species, and I've heard they liked to jump. I only left the little tiny hole open because it needed to be there in order for the wires and the filter to fit. Now that im planning to get another pufferfish, I want to make sure that it was an accident and that there wasn't something bothering him.

Tank size: 15 gallon
temp: 75 deg
plants: Anubis + mossballs
salinity: 1.005
water changes: every week 20%
feeding: i cut a clam in half and fed him once in the morning and once at night. I also fed him some feeder ghost shrimp so he wouldnt get bored.

On a side note, the 15gallon has been empty for a few months with just a guppy keeping it cycled, and now im starting to worry about whether the guppy sustained enough bacteria to support a pufferfish.

Any help advice or information appreciated, thanks in advance

[BumbleBee]

Im also ordering an under water filter so I can cover up that hole. I sort of impulse buyed this one, is it alright for a puffer?
https://www.amazon.com/NO-17-Submersibl ... 007&sr=8-2

[Pufferpunk]

I always disliked internal filters because they take up room inside the tank. If you remove the guppy before adding the puffer, you might be OK or you could just add Tetra Safestart to the filter before adding the new fish.
library/puffers-in-focus/fig8/

[BumbleBee]

Thanks for replying!

What does tetra safestart do?

[Pufferpunk]

It is LIVE nitrifying bacteria. Most other products are dead bacteria in a bottle.

[BumbleBee]

Yuck. Imagine the ammonia from dumping a bottle full of dead bodies in to your tank.

Quick question: How do I dump this nitrifying bacteria in to my filter when its an internal filter and is very difficult to take apart? I do have these 2 huge porous rocks in my tank, which I picked up by the ocean 3 years ago than boiled for 20 minutes. I think most of the bacteria is on there because I switched out my filter a few times, so could I plausibly pour the bacteria just in to the water and hope it lands?

[Pufferpunk]

Pour it near the intake.

OMG, do you have any idea how dangerous it is to boil live rock??
It could release toxic fumes and the pressure buildup inside the rocks could cause them to explode.

Have you tested your water lately?

[BumbleBee]

Um its dangerous to boil live rock? I had no clue. No, i havent tested my water in a while since I dont have a test kit

[Pufferpunk]

You cannot keep fish without testing the water occasionally, especially if it's a newer system.

[ParkerShawn]

I have a new 1" F8 and it will only stay at the bottom. I want it to be more active. I feed it ghost shrimp, freeze dried red shrimp, snails, and bloodworms, what should I do.

[Pufferpunk]

Hi, He's eating OK? How heavily-decorated is his tank?
library/puffers-in-focus/fig8/