How did they break in..

[Haywire]

I love a vague yet curiosity-evoking title; it really gets the clicks!

I am a novice to fish keeping and currently trying to set up a safe aquarium to home 2 fantail goldfish (relying entirely on the internet for information). During this process, I have made efforts to ensure that the aquarium only homes a pair of goldfish...as I type this there is a colony of little white things that I hope to be copepods swimming about and at least 2 snails. After a change of heart, I actually do welcome the critters providing they don't have the intention of aquarium domination. I'm making this thread with the hope that someone could identify the invaders and after some insight explains to me where they could have come from because it beats me.

Some Insight
I first set up the aquarium a while ago and bought plants from the pet shop. I adhered to the excellent advice of the pet store employee when he told me that "the plants will get all the nutrients they need from the water, don't worry about adding anything". Surprisingly, the plants started to die, algae bloomed and bladder snails began taking over. I took everything apart, threw away the plants and gravel and left the tank, rocks/decor, and filter media to dry out. After waiting a month, I cleaned the tank with a vinegar solution and replaced some of the filter media. Then, I added new decorative gravel and re-added the old decorations and rocks (which had been dried out for a month and bathed in very hot water. I bought some tissue culture plants which supposedly are snail free along with liquid carbon and fertilization. A month later (today), I notice the critters.

Expensive box of water:

White Swimmy Things:

I apologise that the camera on my iPad isn't quite up to the task of photographing this. You can just about see the small white swimmers around the decoration. I really hope these are copepods and not some alien unity basing itself in my fish tank.

Snail

Once again, I apologise for the horrific camera quality. If you're able to identify that snail then I'd really like to know if it's harmless or not. If you have trouble finding the snail, I placed a red circle over it. If you find yourself experiencing difficulties locating the circle then I have drawn up some convenient arrows to help point you in the right direction.

General Questions:
How did these things get in the tank?
What are they?
Do I have anything to worry about?

Thanks again for reading and helping out

 

[Ch4rlie]

Copepods are little white round critters with what looks like wings and they have a movement that flits or darts very quickly in jerky movements.

The other option could be planeria, a tiny white worm type creature. Mostly can be seen on the tank glass and pretty self explainatory as you can imagine what worms looks like.

Both these tend to come by overfeeding the tank with too much fish food. Thats the most common cause, simple remedy is to lessent the amount of food youre adding to the tank.

Goldfish or indeed most types of fish will eat copepods and planeria so not too much to worry about. There are varients of planeria though, some are harmful to snails and shrimps but most commonb planeria are the harmless enough ones, just unsightly really and can easily populate the tank quickly.

As for the snails, your picture quality makes this very hard to determine but am fairly sure its likely to be common / bladder / pond snail (differents names but the same specie of snail) as its a very common occurence amongst fishkeepers who buy plants from LFS (myself included but I actually WANT the snails )

Two things spring to mind regarding your new set up for fantail goldfish, thought it worthwhile to give you a useful article on goldfish and their basic care as well as recommended tank sizes - Goldfish for Beginners

And secondly, am unsure if you have cycled this tank and filter or not. Will also add a article on how and why you should do a fishless cycle. - Cycling Your First Freshwater Tank

 

[Haywire]

-Shortened-

Thanks for the response, they must be copepods. They can't have come by means of overfeeding as I don't have any fish in there just yet; I don't usually feed a tank with no fish! Although, I have read that they like environments with algae as a food source so I imagine that could be the perpetrator.

Anyway, I've read both of those articles before even purchasing the setup. Both filters have been cycled over the past 6 weeks as well. I'm wondering what two things sprang to mind about my new setup? I certainly wouldn't want to add the fish if there's a problem

 

[RinaLane]

I just got an empty tank with no plants & yet bunch of annoying snails appeared there too. I just cant stand it sometimes. There is no food but poo from my pleco & yet they thriving! I used completely dry substrate & filter from my main tank with no snails. I dont understand where they coming from. And the only way to get rid of them that I know off & which worked for me before is to get few clown loaches which is way to big to have in 40g with 18" pleco.