Hello there,

I have a 3 gallon aquarium with 4 yellow snails and a betta fish. A friend of mine gave me the snails because she's got too many in her tank and doesn't like the thought of killing them. Anyway, I usually test the water in the tank a once or twice a month, just to be sure everything's okay, and it has always been fine up until now. I've had the betta by himself in the tank for about a year now. Now that the snails have been in the tank for about a month, the nitrate and nitrite levels are in the dangerous ranges. The only thing I'm doing different is feeding the snails 1 or 2 of those small algae wafers every 2 or 3 days since there's hardly any algae in my tank. Am I overfeeding the snails? Am I feeding them the wrong kind of food? Are the snails causing the sudden nitrate and nitrite increase? Do I need to get rid of the snails if there are too many? I tried doing a 25%, then a 50% water change (about a week apart) to see if that'd help, but even though the levels went down a bit after the water change, they went right back up within a couple of days.

Please help!

How big are the snails? If they're over an inch or so in diameter, there is simply too much live animal mass in that 3 gallon tank. You would need a bigger tank. What kind of snails are they if you know? If they are larger species like apple snails, then they will get large and produce a lot of waste. The snails and also any uneaten food are increasing the nitrite and nitrate levels. Nitrite is the main concern. You can do 50% water changes every few days until the levels go down but if the tank is overcrowded, they may never go back to reasonable levels. With adequate biological filtration, nitrite levels should always be zero. What kind of filter do you have? It must not be enough to accommodate the betta and 3 snails. I think your best bet is to get a larger tank.

Ooops! Come to find out, I underestimated the size of my aquarium. I looked it up on the internet and found out that it is a 5 gallon Mini Bow aquarium.

At any rate, each of the 4 snails are about an inch or so in diameter. I've looked at pictures on the applesnail.net to see if I could tell what kind they are, and they look like Yellow Apple Snails (Pomacea bridgesii.).

The filter that came with the aquarium is a Whisper 2-5 In-Tank Power Filter. Would upgrading the filter to the next size up (say, for a 5-15 gallon aquarium) help much? Even though I would LOVE to get a larger tank, I really can't because I live in a dorm and they don't allow us to have anything bigger than a 5 gallon tank. :( I don't want to get rid of the snails, especially since they were "rescued". If getting a "bigger" filter won't work that well, are there any additives or chemicals that're safe to use over extended periods of time and effective in keeping the nitrate/nitrite levels in check?

I've read that live aquatic plants can help with the nitrate/nitrite levels. Would adding a few to my tank help very much, or is their impact on the nitrate/nitrite levels only minimal? If they would help much, is there one type of plant that does a better job than the next, or do most people just get the ones that look and fit best in their aquariums? Applesnail.net says that the yellow apple snails prefer dead or rotting plant material rather than live, healthy plants... so my snails shouldn't feed much on the live plants, right?

I'm sorry for having so many questions. I never thought that 4 snails could cause me so much worry! :unsure:

Thanks so much for any input and suggestions.

While a larger tank would be better, getting a larger filter will help some so do that if you can. I thought I had Pomacea bridgesii as well but it turns out I have the other kind that eats plants! If you really have the P. bridgesii, then they might leave some live plants alone. If you have another kind, the plants won't last but a day! The live plants will help with nitrate levels a little but probably won't effect the nitrite levels. Before you added the snails, the tank was probably cycled (meaning there was enough good bacteria in the tank and biological filter) but with the moderately-sized snails, the bioload went up. You need to provide substrate for the good bacteria to grow in a larger filter. Adding more things (any kind, the more porous, the better) to the tank also gives more places for bacteria to grow.

There aren't really any chemicals you can add to remove nitrite and nitrate. Nitrate is not very toxic so water changes are enough to keep that in check. Ammonia and nitrite are pretty toxic. In addition to water changes, the addition of aquarium salt (a tablespoon per few gallons for water that is changed out) will reduce the toxicity of nitrite. There may be special or resin filters that can remove nitrite but those woudl be hard to find and cost $100's.

If you want to try live plants, see http://www.fishpondinfo.com/decor.htm
Plants aren't my forte though. You would need intense lighting, perhaps fertilization (which could worsen the situation), etc. Plants that grow well even with not the best light that I keep in my tanks when everything else rots include floating frogbit and java moss. Both will suck up nitrate and grow like mad if not eaten.

Okay. I got a bigger filter today... one for a 5-10 gallon aquarium, so I hope that at least helps some. The store didn't have any healthy looking plants, but the clerk said that they should get new shipments in by Thursday. All of the decorations they have are made of some sort of poly resin. Would that suffice? In the meantime, I guess I'll keep checking the water levels and do partial water changes as needed. I'll also put word out about giving away 2 or 3 of the snails. Those darned lil' creatures! :rolleyes:

Good bacteria will grow on any surface including resin. More will grow on surfaces that are more rough and have more surface area. Maybe you could add a piece of decorative lava rock full of lots of small holes.

I have a small lava rock, but I was leery about putting it in with the snails, because the rock is very rough and has sharp edges all over it, and I didn't want it to cause the snails to get hurt. I'll add it in and hopefully things will start balancing out again.

Maybe you can file off the sharp points. Snails normally don't get cut on rocks. It's usually spawning fish that get cut.