Next plant

Leaf close up on second plant.

Third plant.

Fourth plant.

Fifth plant.

Petco is notorious for selling bog plants as aquatic plants. I'll take a stab at id's:

#1 pic looks like an anubias coffeefolia - aquatic
#2 & 3 look like 'banana' plant - bog
#4 at first I thought java fern, but the runners makes me think sagittaria - aquatic
#5 ? another java fern, sagittaria or sword - if so aquatic
#6 no idea but probably a bog plant

#1 A java fern of some sort?
#2 looks like an anubias to me, possibly anubias barteri
#4 I wanna say an Aponogeton hybrid
#5 A sword plant, possibly amazon sword?
and #6 looks like a water onion

these are just my guesses, keep this in mind!

I don't know its name, but I have found the third plant to be very vigorous - to the point of really taking over the whole tank. We always called plant #2 a banana plant.

1. Java fern (microsorum pteropus)

2. Banana plant (Nymphoides aquatica)

4. Aponogeton sp.

5. Amazon sword (echinodorus amazonicus)

6. No idea but its not an onion plant