"Snail - In" Cycling!

Hello All,

When I returned to fishkeeping in 2014, I decided on a fishless cycle, with loads of plants, for my 125L . As the cycle progressed, I couldn't help but notice how the increasing numbers of hitch-hiker pond snails seemed to cope admirably with high levels of both ammonia and nitrite. The solution, after cycling, was 2 assassin snails, which were eventually removed, together with their offspring, to a 12L cycled, but unfiltered, plastic tank. They have been in there for eighteen months now, but despite feeding with a variety of relatively high protein foods, and the occasional pond snail from the other tanks, they don't seem to be thriving.

So, a few days ago, I decided to set up 2 feeder snail "tanks". I purchased two cheap plastic 5L containers, set them up on a window sill, unheated and without substrate, and added large clumps of elodea crispa to both. To one, (tank B) I added a piece of mature, algae covered cuttlefish bone, and to the other (tank A) some fresh ground cuttlefish bone. To each I added half a dozen pond and small MTS snails.

Today I decided to test the parameters:
Tank A - ph 7.6,   NH3 2, NO2 2 Temp. 20deg C
Tank B - ph 7.6,   NH3 0-0.25, NO2 0-0.25. Temp. 20deg C

Fascinating!

Large w/c's were done on both tanks. I can only assume that the mature cuttlefish bone had made the difference with regard to bacteria, whereas the elodea, which came from an established LFS tank, had insufficient bacteria. The snails do not seem to be too concerned. I will now monitor both tanks daily.

                                     Skittler

I've been having some fun with assassin snails too.  Not as scientifically as your experiment though which was nicely done. 

Consider the effect of the algae in tank B.  It would have helped as algae can process all three forms of nitrogen used in the cycle, NH3, NO2, and NO3 with most preferring the NH3 first.  Large water changes would mean plenty of nutrients for the algae too. 

In my Papua New Guinea tank I have brown algae and I'm happy to let it grow.  It looks a bit messy but as I'm going for a natural biotope it fits right in.  I put 7 assassin snails in there to clean up frozen foods uneaten by the fish as they prefer that over the algae.  Even after a week the water is at NH3 0, NO2 0, and NO3 at 5 ppm.

You haven't mentioned if the experiment tanks included filtration?  Without filtration the work would have been done mainly by the plants/algae and not bacterial colonies from a filter.  With no substrate or decorations in the containers there'd be reduced surface areas for the bacteria to grow.

Elodea crispa is a root feeding plant (though root feeding plants primarily feed from water column) so alone would not be as efficient as the purely water column feeding algae.  If you want to repeat the experiment try with a good water column feeder such as floating plants.

I like seeing snails/algae in a filtered cycling aquarium as its a good indicator that the aquarium is alive.

Here's a pic of a burrowing assassin snail I took two days ago.  Wasn't sure if I'd use it anywhere but he was so obliging.

I have a tank for breeding snails for my dwarf puffer fish. As you can imagine, the mouth of a dwarf puffer is quite small, so I only tend to harvest the young snails, leaving the adults to continue breeding.
Currently the snails have the old betta tank, a 34l tank, with a filter and heater set to around 24 - 25C. I don't harvest on a regular basis, I just transfer all the little ones into the dwarf puffer tanks when I remember. As you can imagine, 16 dwarf puffers can go through quite a few snails, and it takes the snails a while to get the numbers back up again.
In the past I've had the snails in both my 19L and 24L starter tanks, and just move them around between tanks depending on circumstances, with and without heaters depending on the time of year.

@Matt I've never thought about it. The gang are mainly fed on live bloodworms (from a feeder pod) a couple of times a day. Dwarf puffers don't have the sort of trouble with their beaks growing, the way that the larger puffers do, but some chewy/crunchy food always helps, so I just use the snails as a treat in addition to their bloodworms, to help keep their mouths in good condition, and give them the entertainment of hunting for their food. I've never seen snails in the puffer tank, so I'm guessing that everything that I put in is consumed before it can grow up, but then I'm also guessing that, if there were lots of snails available, the puffers would just eat everything until they got fat, and still come to the front of the tank to beg when they see me.   

Perhaps 2 baby snails a day per fish would work, and I'm only guessing this based on the size of baby snails and the size of the fish, like you would with fish & flake/pellet food. The problem with snail breeding then is always having appropriately sized snails available, but I guess regular harvesting would help with that.

Sorry I can't provide a more accurate answer.

@Skittler I don't think that dwarf puffers absolutely have to have snails, but I couldn't get them to eat anything like prawns, mussels, etc. and I think it's a good idea to provide them with something a bit harder to deal with than the bloodworms, aswell as a bit of variation in their diet. I started off just picking pest snails out of other tanks whenever I saw them, and putting them in the puffer tank. For some reason my gang are reluctant to eat anything that doesn't move, so things like snails are ideal. I also use live daphnia occasionally, but as the snails are free they work out as great value for money.

Hello All,

Both tanks dropped to 18deg C last night, so they have been moved to the kitchen, which will be warmer, but not so much light. Also, I have left the terracotta rings and sponge packing from the plants in the tanks, in the hope that they will provide more surfaces for bacteria.

Today's tests:

Tank A   NH3 0.5   NO2 1-2             - large w/c
Tank B   NH3  0     NO2  0               - small w/c

It does look as though Tank B is "snail cycled" already.
I have just added some top filter pad squeezings from the 125L to Tank A.

                                     Skittler

Latest checks:

Tank A    NH3 0.25   NO2 2
Tank B    NH3  0      NO2 0.25

Water changes continue. Have seen pond snails mating in both tanks. All the snails seem to be growing rapidly, although the (nocturnal) MTS are not so much in evidence during the day. I still find the difference between the two tanks interesting. I will be doing a w/c on the 125L shortly, and I will add more filter squeezings to both.

                                      Skittler

Yesterday I added 4 potted plants from MA - 2 x anubias nana and 2 x crypts. One of the anubias looks big enough to divide. I have left them in their pots for the moment. The tank is very clear, and the snails can be seen motoring about.

Today's tests:

NH3  0, NO2 0.5

Seems like progress.

                                       Skittler

Plants do a lot to help. A few weeks ago when I forgot to turn my filters back on and only found out 24 hours later, I had zero ammonia and nitrite with an overstocked tank. It can only be due to bacteria on all the surfaces and the plants. The water sprite just about covers the surface of the tank, and floating plants are well known for sucking ammonia and nitrate from the water.

Nerite poo is quite bulky, especially if there is wood in the tank