Can Snails Mess Up A Fishless Cycle?

[curious_k]

Hi all. Cycling a 25 litre tank intended for a betta.
 
I've been using household ammonia (Kleen Off) and all was going well - ammonia and nitrites dropping to almost 0 within 24 hours after about 5 weeks. However, there's a piece of bogwood in there from the pet shop and it appeared a snail or two hitched a lift.
 
I'm sure you can guess what happens next... I go away for a weekend and return to a billion snails. Been hoking them out using spinach leaves overnight.
 
Anyway, I also noticed sometime during the week that my ammonia levels shot up. They were at least 4ppm on Thursday morning. Haven't added any ammonia, and they're now back down to 1ppm or so. The nitrites are 0 and nitrates are a little over 5.
 
Question is: have I screwed my cycle by going away for a couple of days and bacteria dying off? Or have I screwed my cycle because there are snails? What should I do next?

 

[Ch4rlie]

I think you should be ok about snails in your tank during the cycle, as snails do not have a real high bioload.
 
Basically just means it may a tiny bit longer to cycle your tank completely, I would suggest you carry on taking out as many as you can in the meantime using whichever methods suits.
 
EDIT - if you're looking to offload lots of common snails, I can take them off your hand as I have assassin snails that would be happy to have a feast on them This is if you are willing to do so and if you are UK based.

 

[curious_k]

Thanks. I'm mystified as to where the ammonia surge came from, but maybe I just overdosed the tank after not feeding it for a couple of days. /
 
Most of these snails are baby tiny ones so probably not interesting to your assassin? And bloody hard to catch.

 

[Blough]

I think that snails are really sensitive to water chemistry. Seems to me that cycling a tank with snails in it isn't humane to the snails, kind of defeats the purpose of a fishless cycle, and is a good way to end up with dead snails. If possible, wait until your tank is fully cycled before adding any fish.

 

[curious_k]

Blough - I didn't add them on purpose, I don't want them!
 
I understand the cycling process and the importance of not adding fish until the end. My question was, now that snails have sneaked in there without my knowledge and are hard to eradicate, how are they affecting the cycle that has already started?

 

[Blough]

Oh, pond snails! I though you were talking about snails that you get at the store like mystery snails and apple snail.

 

[curious_k]

Aha! Sorry, I should have specified. Yeah, they're pond snails and they're everywhere.

 

[curious_k]

Updated readings this morning: ammonia 1, nitrite 0, nitrate 160 (I didn't shake it enough yesterday).
 
This ammonia just doesn't seem to be budging. The pH is 7.4 which I understand to be high enough.
 
Should i do a pwc? I've read conflicting reports about nitrate being very high and whether this stalls the cycle.

 

[Ch4rlie]

What test kit are you using and are you adding anything else to the tank other than ammonia?

 

[curious_k]

Nope, only adding ammonia. API master test kit.

Ammonia has finally dropped to 0.25, wondering whether to add more so the bacteria can feed, or do a water change to get the nitrates down a bit first.

 

[Gruntle]

Don't worry about feeding your bacteria, they'll be fine and dandy for a few days. I'd continue with your snail eradication, get the tank to cycle within 24 hours and then do a water change.
 
Actually, if you're concerned, since your tank isn't huge and a water change shouldn't be too much trouble, do a water change now. Nitrates shouldn't affect your cycle, but 160ppm is getting quite high.
 
Higher than 1ppm ammonia may kill your snails, which in turn will raise your ammonia as they decay. Which in turn may kill your snails. And so on. So keep removing the snails and get your ammonia down to zero before re-dosing.
 
Sorry if that's a little clunky, I keep getting new ideas as I type.

 

[curious_k]

Thanks! Did a small (10%) water change which hasn't affected the nitrate reading really / but will leave it for now.
 
Ammonia had hit 0 by this morning, so I've redosed it to the 4ppm I've been using to cycle, and will see how long it takes to go. Really hope the cycle isn't restarting.
 
Some sites say that it's cycled when amm + nitrite disappear in 12 hours, some in 24. Can anyone shed light on that??

 

[Gruntle]

Generally it's 24 hours according to this site. Be also aware that 4ppm ammonia is probably more than a fish setup will ever produce.
 
The idea is to have a strong enough bacteria colony to process the ammonia (and then nitrite) as the fish produce them. Fish (and snails) produce ammonia constantly, so the bacteria are always processing. 3ppm is probably the maximum a reasonably stocked tank will ever produce at any time, but it also gives a buffer (for instance if a fish passes away during the night and you don't notice it until the morning).
 
And a 10% change won't dramatically affect the nitrate reading. If you have 160ppm and change 10%, your nitrate will drop to 144ppm.

 

[curious_k]

Yeah this is the other aspect in which advice seems to vary a lot - I did wonder whether 4ppm was a bit high. The online guide I started with advised 4-5ppm.
 
I'll reduce it to 3ppm for next dose and see how long that takes. Will go with 24 hours if that's worked for everyone here.
 
Haha, very good point on the water change. It was determined by 'size of jug' rather than 'common sense'

 

[Ch4rlie]

Yeah this is the other aspect in which advice seems to vary a lot - I did wonder whether 4ppm was a bit high. The online guide I started with advised 4-5ppm.
 
I'll reduce it to 3ppm for next dose and see how long that takes. Will go with 24 hours if that's worked for everyone here.
 
Haha, very good point on the water change. It was determined by 'size of jug' rather than 'common sense'

 
5ppm used to be the normal dosages of ammonia, this was until the cycling regime was revised and found that anything over 4ppm has a risk of stalling a cycle. Of course some variables has to be factored in for this to be a real risk, i.e very soft water.
 
I would advise you to stay at 3ppm maximum for your cycling as per the cycing article routine, in fact for a 25 litre tank perhaps 2ppm is to be considered since there will be very little stocking that can be added to this size of tank. As this tank will not be able to contain many fish or shrimps hence the bioload will be lower.
 
3ppm of ammonia is far more than any fish, shrimps, rotting plants etc will ever really produce in most tanks, in fact 2ppm is rarely reached in a normally stocked aquarium. The reason for 3ppm ammonia doses for cycling is to doubly ensure you have built up enough bacterial colony to deal with fully stocking the tank once it has completed cycling. The surplus bacterias simply go dormant or die off until the equilibrium for individual tanks is reached.
 
Once the cyce has been succesfully completed, change as much as water as is possible, this will get rid of high nitrate levels and makes for a nice clean dechlorinated water in the tank for adding new stocking to the tank (the best bit

)
 
Then for water changes once the cycle has been completed and stocking added, generally speaking, most aquarist will change between 30% to 50% of tank water volume weekly, sometimes more depending on the current stocking and species etc. Main reasons for water changes is to reduce the level of nitrate (especially in non planted tanks) as well as to give the tank stocking nice fresh clean water and replenishes vital minerals.