The Puffer Forum

Hi. I am a college student and this is my first pufferfish. He’s a figure 8 Puffer named Lump, and he’s honestly helped me so much getting through college. I like having someone to talk to!

1) I did notice Ammonia might be a little high. About .2 I did a water change. I also noticed the Gravity is possibly slightly over 1.008 so I’ll try and bring it down slightly. I have no idea how that happened.

2) I have him in a 10 gallon. I’d up it if it was a option but unfortunately it’s not. there was previously a guppy in the tank (the store owners gave it to me after accidentally scooping it with the puffer) but I think Lump ate the it. This was about a month ago.

3) I mostly feed mealworms and snails, but I absolutely can switch it up. I do water changers maybe every other week, but I heard I might need to up that.

4) I haven’t made any changes that I can think of honestly. Which is surprising with how sudden this was.

5) The tank has been set up only for about 3 or 4 months. I thought it was fully cycled, but based on the ammonia, maybe it wasn’t?

Last night my Puffer began acting strange. Hiding in the back of the tank, and not eating. I was confused but not too worried since he ate fine that morning (I had given him one small mealworm that morning). But this morning he’s barely responding to me. His eyes also seem flat if that makes sense. I’m honestly super worried because of how sudden it was. I’m worried about leaving for class! I did a 25% water change in a panic, but I don’t even know if that was the right thing to do! I have never used a forum before, so I apologize if I made any mistakes in this post, but I am very worried. He’s my friend.

Water changes are NEVER wrong. Get Tetra Safestart (Walmart may carry it) & add it directly to your filter, after a 50% WC. When he's feeling better & the tank is stable, change out that gravel for aragonite sand. This will stable the pH around 8. Mealworms are extremely difficult to digest. I suggest earthworms (again, Walmart).

Pufferpunk wrote: ↑Mon Mar 02, 2026 12:37 pm Water changes are NEVER wrong. Get Tetra Safestart (Walmart may carry it) & add it directly to your filter, after a 50% WC. When he's feeling better & the tank is stable, change out that gravel for aragonite sand. This will stable the pH around 8. Mealworms are extremely difficult to digest. I suggest earthworms (again, Walmart).

Hi! So sorry for the late reply. He unfortunately passed within an hour of posting this. I was really heartbroken and wanted to wait till I felt a bit better before returning. I’m thinking the salinity got a little too high, and that was the main problem. I really appreciate your tips. I adjusted the water a bit and have switched to using distilled water opposed to tap water with dechlorinator. The water literally tastes off here, so I think this will be helpful rather than test for every possible thing that could be in it. I did get another F8 puffer. I ordered him online and he is super active and eating great! Speaking of food, thank you so much for the info on mealworms. I didn’t realize they were so hard on them! I actually just got him some frozen shrimp, and hes been destroying the snails I put in! I’ll look into the argonite sand as well!

I was also wondering, do you know if shelled oysters are a good option? I got a container of them but I wanted to check before I gave him any. I heard a varied diet is good for them, so thought I’d mix it up. Ps I checked the container and it’s says it’s just oysters and water - no seasonings or added salt or anything. I’ll try earthworms too! I go fishing so I have plenty in my fridge I’ll just rinse them really good.

One other thing, I don’t think my last F8 was completely healthy. He had lots of bites and nicks, and I wasn’t completely confident he would fully heal. Most of the bite marks healed with some Melafix, but the fin bites were being a lil slower. My new puffer has no bite or nicks! I also believe he’s a bit older!

Thank you so much and sorry I took so long for me to come back!

I'm glad you got another one! Those oysters sound fine.