Are snails a good thing or a bad thing?

[Yossu]

Went to our local park to harvest some duckweed for our goldfish tank, and predictably, some snails came out with the duckweed. Just wondering if I'm going to cause myself problems by putting these in the tank. Not sure what kind they were, but at least one was about 3-4mm long with a twisted conical shell, and some others were smaller with a flatter round shell.

On the one hand, snails eat algae, which can only be a good thing, but on the other, they breed like, well, like snails! I don't want to get overrun with them.

Anyone able to advise?

 

[sharkweek178]

I don't generally believe in the concept of a clean up crew when it comes to fish. But snails make for a nice little cleanup crew. They get into places we can't get into and break down organic matter.
Snails populate up to their food supply. Overfeeding is the biggest reason people get a lot of snails. If you don't overfeed, keep algae under control, and prune dead plants; that should go a long way towards keeping snails from breeding out of control.
I like to think of snails as a bellwether. If I see a lot of them, then that means there's an issue with my tank that I need to address.

 

[Colin_T]

DEATH TO SNAILS

Post a picture of the snails so we can ID them.

Some snails are ok and not a real problem but other snails are a pain in the blank and should not be allowed in aquariums because they are pest species.

 

[Yossu]

Thanks to both of you for the replies. I like the idea of the snails giving me an idea of how the tank is doing.

@Colin_T Looking again, I can only see one type of snail, picture below...

I'm sure there was one with a conical twisted shell, but I can't see it now. There's also a dead bug in there! Should I remove that, or will the fish just eat it?

Thanks again.

 

[Uberhoust]

I used to worry about introducing snails. I have them now and they are not causing any issues, kind of like them in the tank.

 

[GaryE]

I hate snails in a tank. The conical one has probably burrowed under the sand. The pond snails will breed like mad, given a chance. They're ugly, and as they die, they pollute the water. They do nothing useful that couldn't be accomplished by a fish or by you. No, let me backtrack - there's one thing - they can provide food for assassin snails.

Duckweed is almost as bad.

As you can see, there is no consensus, and a range of opinions. I am an anti-snail extremist.

 

[Yossu]

I hate snails in a tank. The conical one has probably burrowed under the sand.

No, it's still in the plastic tub I collected the duckweed in. Haven't put anything in the tank yet, wanted to hear from the experts first.

Could be I was mistaken when I looked, could be it's in amongst some of the bits of muck that came out with the duckweed.

Duckweed is almost as bad.

Oh I quite like duckweed. It's easier to control than snails, as it floats on the surface, so you can just scoop it out if it becomes a pest.

As you can see, there is no consensus, and a range of opinions. I am an anti-snail extremist.

So I see on both counts!

I think I'll try and avoid the snails. Not sure I want to go down that line. I can always add some at a later stage if I change my mind.

Thanks to everyone for the replies.

 

[MaloK]

&

 

[Yossu]

Ha, so much for duckweed taking over the tank! I spent ages carefully cleaning some duckweed, making sure there weren't any snails in it, then dumped it into the tank.

They haven't eaten all of it yet, but there's not much left!

 

[Fishmanic]

The only snails I like are zebra nerite snails. They devour algae and look nice too. I just got 2 of them for my Betta 5 gallon tank. The good thing is that they wont breed unless you have brackish water.

 

[Yossu]

The only snails I like are zebra nerite snails. They devour algae and look nice too. I just got 2 of them for my Betta 5 gallon tank. The good thing is that they wont breed unless you have brackish water.

That's good to know. I have been looking at various variations of nerite snails, and rather like the look of some of them, zebra nerites in particular. We don't have brackish water, so I guess breeding won't be an issue.

Thanks

 

[Essjay]

A female nerite will lay eggs everywhere - they look like small sesame seeds. But they won't hatch, they just stay there. These eggs can be scraped of hard things like glass, the plastic parts of filters, plastic decor, rocks etc but not plants or wood (the top layer comes off wood if you try - been there, done that....)

Nerites are also near impossible to sex by looking at them in a shop tank, and of course with mail order you get what you're sent.

 

[Nells250]

My two nerite snails are GREAT for controlling algae BUT they do poo more than shrimp... or at least I THINK they do!

 

[Essjay]

Yes nerites do poop a lot, especially when they've been grazing on wood as they seem to rasp the surface off with whatever else they're eating.

 

[OnlyGenusCaps]

I am not a fan of all snails. And many of the drawbacks of various snails have been brought up above. However, if I may be so bold as to make a pitch for one snail... I like rabbit snails. They are surprisingly good at eating many types of algae, particularly if you have them in numbers. They add visual interest, and can have colorful skin. They breed slowly, and give live birth (no pesky nerite-type eggs on the glass, or gross globs of mystery snail eggs at the surface). And I've never seen signs of them eating fish eggs, for those of you who breed fish as I do. Overall, they are my preferred freshwater snail. The only down side I have found is that they do not tolerate aggressive fish well - so don't put them in with your mbuna. That doesn't go well!

FWIW, I also prefer snail based CUC in reefs tanks. But death to CUC crustaceans! Unless they are in the fuge, then I'll give them a pass.