So my 7 year old has a small aquarium we've had running for maybe 3-4 months. It's freshwater and maybe a 8-10 gallon tank max. It's got x3 small little fish in it (No clue what kind).

He loves SpongeBob so I grabbed a snail from the local pet shop and named it Gary. Watching the snail chomp algae and clean the tank has been a real treat. He's been in the tank for about a week & half. Today I saw x3 tiny little plants floating on the water. Best I can tell from internet research the look like duckweed.

I'm assuming that they somehow hitchhiked in with Gary the snail. Should I allow these to stay and grow some or remove? I know nothing about tanks!

When i kept tank, I had some duckweed floating around on the surface off and on over the years.

Duckweed is fine and nothing to worry about....just scoop up the extra after it multiplies and appropriately discard what you dont want.

I would be more worried about WHAT ELSE may have been introduced with the snail / fish from the store you shop at. I got to be a bit of a snob and only shopped at reputable aquarium shops so as to reduce (at least in my mind anyway) the chances of inadvertently importing a parasite or disease to my tank. No saying yours wasn't reputable but I mention it so as to give you something else to consider in the future if you haven't considered that angle already.

Remove it until you make a decision, once it gets established its pretty hard to get rid of.

I personally don't like it, I have a planted aquariums and I feel like it blocks a whole lot of light and I get tired of scooping it out. I have a friend that likes it though and adds it to all of his aquariums.

Duckweed isn't harmful, it's more of an aesthetic issue.

A separate thing to note - sometimes those snails can look completely dead, for long periods (weeks) of time, upside down, then suddenly come back to life and start moving.

We had one that we were certain died about 15 times, including a high dive attempt out of the tank. Didn't kill him.

I think he is finally dead though. There is a hole in the shell where he used to be. I'm not throwing it out though. You never know.

The worst places to buy fish from are the ones where all of the tanks are connected and the water flows from one tank to the next to the next. Like at Pet Stupidmarket. If one fish is sick it carries it to all of the tanks.

I would not buy fish from a pet store. Buy from a trusted breeder. I have been raising and keeping Discus for 20 years. The fish from pet stores almost always have parasites or some other illness. If you must buy from a pet store, quarantine your new fish in a separate tank until 100% sure they are healthy.

Duckweed is one of those things that can get out of hand and become impossible to eradicate. I would recommend you do your best to get ALL of it out now and keep checking for new ones that may pop up.

Duckweed is the fastest growing plant know to man, much greater than kudzu or bamboo. It will take over a pond if not controlled. Not sure about your fish tank, but many a farm pond has been lost to it.

About a hundred years ago I was in the garden center/ landscape business and one of my duties was introducing and running the water garden department.

One of the several plants customers would sometimes buy and add to their water gardens was duck weed.

Duck weed can grow quickly and take over, but in a healthy water garden it can usually be managed with out too much trouble.

If I recall correctly, zones with prolonged Winter cold snaps would kill off Duck weed, so it was used as an annual plant and really wasn't around long enough to cause much of a problem.

I don't have any experience with Duck weed in acquariums, but there were times when some of the pump filters that I maintained would get clogged with various debris and decomp and sometimes Duck weed would work its way in as part of the crud that needed to be removed, so I would assume that may also be true for acquarium pumps as well.

Duckweed can be beneficial if the fish you have come from a low light environment (think Amazon River in flood season). Specie such as Angels, Discus, Apistograms et al.

it isn't hard to control, when I have it and it gets more cover to the tank than I want I scoop it out with a fish net and put it in the compost bin (makes great compost).

That said I don't care for it as much as I like floating red root or other floating plants.

Aquatic plants in an aquarium can help keep nitrates down and by doing this keep algae down.

Personally I would worry more about the snails. Slow living things tend to give parasites a platform to grow and multiply easier.