Just a few questions about pea puffers 🙂

1~ Would a single pea puffer be okay in a 5.5 gallon walstad, I've heard they're messy but do they need a filter?

2~ I know they like live annnd frozen food but what exactly, there's blodddworms, brine shrimp, snails, mysis shrimp etc what one(s)?

3~ If pea puffers are not suitable for a 5.5 gallon walstad tank what would be?

Shrimp and/or snails are pretty important to a Walstad. A pea puffer will destroy both. I would not put one in a no filter tank.

I have ricefish, shrimp and snails in a Walstad. Other good choices include whitecloud minnows or endlers if you include a heater.

A single Betta may also be nice in a tank like that, depending upon dimensions, water parameters, temperature, all the things they require.

Thanks, I was unsure about the no filter aspect. I like ricefish, however they are impossible to find in the uk 😞 I've read wcmm's need a 10 gallon minimum?

What wattage heater would I need?

1~ For volume 1 pea/dwarf puffer is fine.I'd personally strongly recommend a filter as they are messy eaters (snails-they don't eat all the meat basically just bite off the heads and leave the rest to rot..) unless you are COMPLETELY PACKED with fast growing plants and/or aggressive with water changes multiple times a week.

2~They definitely prefer live over frozen-some will learn to take frozen (some don't). Live snails Malaysian trumpet snails, ramshorns, pond snails, bladder snails-they don't care they'll eat them all (and eat they eyes/antenna off large species like mystery and nerite snails so do not keep those in there). Get a live black worm culture, put half in the tank and half in a tub of water you culture (cool place, filter is a bonus if a large culture, feed fish food, or even organic brown paper bags (no glue parts) or keep in fridge and change water frequently (and remember to feed). If you keep in the fridge dont.skimp.on.water.changes!) Other foods include daphnia, brine shrimp, vinegar eels, white worms, grindal worms (look up soilless culture options here-good way to avoid mites).. pretty much any of the 'small' species culture foods for fish. Ps: they will eat shrimp. I've seen a video of a group of pea puffers taking apart a live amano shrimp..

3~Are you going to use a heater? Whats your pH hardness, tds? There are plenty of things depending on water/if you'll heat or keep temp consistent including but not limited too (not to keep together-choose one):
betta splenden (all those store bought in a cup kind-don't get the 'king' aka half giants they need larger tanks)
neocaridina shrimp
caridina shrimp
IMO they should have a 10g or more but people keep these in 5g (group of 6 min recommended):
pygmy cory
chili rasboras (Boraras brigittae)
Boraras maculatus
guppies/endlers
celestial rasboras (Danio margaritatus)
I'm too tired to think of others right now (I have too high a ph for most small species so don't know them off the top of my head 'cause.. i can't keep 'em).
various kilifish (LID!)

In my experience, when I had added a puffer to my tank the MTS quickly learned to stay in the substrate during the day, and only came out at night when the he was asleep. So the puffer had to content himself with bladder snails and the less astute MTS. After I had to evict him for bad behavior, the MTS start being visible during the day again.