Tank was cycled, but now I'm not sure.

[I_Smell_Fish]

My 15 gallon tank was cycled and contained 1 male betta, 7 pygmy cories, and 1 nerite snail and water parameters of Ammonia 0, Nitrites 0, Nitrates 5.0. My betta died so I added 3 mollies with plans to add 3 more in a few weeks. Now my parameters read Ammonia 0, Nitrites .25, Nitrates 10.0.

One other thing I did yesterday was to remove the carbon from the filter and add PhosGuard to remove silicates that are causing diatoms. The instructions said to remove the carbon and leave the PhosGuard in place for at least 4 days.

Why the nitrites? What happened? How do I get rid of the nitrites?

Thank you in advance!

 

[Baker]

Your BB levels are going to need to catch back up the the newly introduced levels of waste from the 3 mollies.
Mollies are quite heavy waste producers

 

[I_Smell_Fish]

Thank you. One molly isn't working out so I think I'll take him back and perhaps that will help.

Thank you

 

[Byron]

Thank you. One molly isn't working out so I think I'll take him back and perhaps that will help.

Thank you

A 15g tank is insufficient space for mollies, so I recommend you return them. Mollies are not small fish, attaining 3 inches for males with females reaching 5 inches (6 inches is not uncommon). And as others noted, they have a significant impact on the bioload; being primarily vegetarian, they eat a lot and that means more waste.

Mollies should be housed in at least a 30-inch tank (like a 29g) but this is still pushing it and a 3-foot tank is preferable for healthy fish.

Byron.

 

[I_Smell_Fish]

A 15g tank is insufficient space for mollies, so I recommend you return them. Mollies are not small fish, attaining 3 inches for males with females reaching 5 inches (6 inches is not uncommon). And as others noted, they have a significant impact on the bioload; being primarily vegetarian, they eat a lot and that means more waste.

Mollies should be housed in at least a 30-inch tank (like a 29g) but this is still pushing it and a 3-foot tank is preferable for healthy fish.

Byron.

I won't have the mollies long enough for them to reach full size, or anywhere near it. My tank is cycled but I want to increase the bioload so I can add 5-6 female bettas at one time. I explained this above. Thanks!

 

[Byron]

I won't have the mollies long enough for them to reach full size, or anywhere near it. My tank is cycled but I want to increase the bioload so I can add 5-6 female bettas at one time. I explained this above. Thanks!

I'm not following you here. In post #1 you stated you have 3 mollies and intend getting 3 more in a few weeks. No mention of female betta. So, seeing this, I tried to prevent trouble by pointing out that a 15g tank is not sufficient room for 6 mollies, or even 1 for that matter. We can only offer suggestions based on what is posted.

 

[I_Smell_Fish]

I'm not following you here. In post #1 you stated you have 3 mollies and intend getting 3 more in a few weeks. No mention of female betta. So, seeing this, I tried to prevent trouble by pointing out that a 15g tank is not sufficient room for 6 mollies, or even 1 for that matter. We can only offer suggestions based on what is posted.

Sorry if I wasn't clear. I was just talking off the top of my head and didn't really prepare anything. But yes, I do plan to trade these 6 mollies out for 6 female bettas after the mollies has established the tank for 6 fish.

 

[Byron]

Sorry if I wasn't clear. I was just talking off the top of my head and didn't really prepare anything. But yes, I do plan to trade these 6 mollies out for 6 female bettas after the mollies has established the tank for 6 fish.

This sounds like fish-in cycling. Are you keeping the mollies?

 

[I_Smell_Fish]

This sounds like fish-in cycling. Are you keeping the mollies?

I don't use fish to cycle a tank. The tank is cycled and I'm adding mollies slowly to increase how many fish the tank can handle without starting a cycle. And no, I'm not keeping the mollies. When I have 6 mollies in the tank I will take them out to add 6 female bettas at one time. I will rehome the mollies. I'm particular about where my fish go.

 

[Byron]

I don't use fish to cycle a tank. The tank is cycled and I'm adding mollies slowly to increase how many fish the tank can handle without starting a cycle. And no, I'm not keeping the mollies. When I have 6 mollies in the tank I will take them out to add 6 female bettas at one time. I will rehome the mollies. I'm particular about where my fish go.

I'm not just arguing, there is an issue here that I don't think you see. This is a form of fish-in cycling however you look at it. And mollies are one of the worst fish to use, because they are very highly susceptible to any ammonia or nitrite above zero. Any fish will be affected, but some like mollies much more permanently than others. For the sake of the fish, it would be better not to proceed with this.

Also, I oppose any acquisition of fish with the intention of not keeping them permanently. This too is highly stressful on fish. The netting of a fish triggers the same serious level of high stress that escape from a predator triggers, and this is damaging to the fish.

Another possible issue is the GH and pH, which are not given. Mollies need moderately hard or harder water, and in soft or acidic water they will be internally affected, again permanent depending upon the levels and exposure time. I spotted this because the other fish mentioned in post #1 are all soft water fish, some of which would not manage well in water as hard as it should be for mollies.

 

[I_Smell_Fish]

I'm not just arguing, there is an issue here that I don't think you see. This is a form of fish-in cycling however you look at it. And mollies are one of the worst fish to use, because they are very highly susceptible to any ammonia or nitrite above zero. Any fish will be affected, but some like mollies much more permanently than others. For the sake of the fish, it would be better not to proceed with this.

Also, I oppose any acquisition of fish with the intention of not keeping them permanently. This too is highly stressful on fish. The netting of a fish triggers the same serious level of high stress that escape from a predator triggers, and this is damaging to the fish.

Another possible issue is the GH and pH, which are not given. Mollies need moderately hard or harder water, and in soft or acidic water they will be internally affected, again permanent depending upon the levels and exposure time. I spotted this because the other fish mentioned in post #1 are all soft water fish, some of which would not manage well in water as hard as it should be for mollies.

Won't adding mollies slowly avoid any ammonia appearing? I've had many tanks over the years and often added a couple more fish to an existing tank without problem. Are you saying that any increase in fish in a cycled tank will cause ammonia to spike?

Also, I have hard water. Ph is 7.5.

I'm taking steps to rid the tank of the trace of nitrites....asap.

Mollies are very hardy fish, I'm told by my lfs.

I won't net them. They're pretty easy to catch with a large cup that I have.

Thank you for caring so much!

 

[Byron]

Won't adding mollies slowly avoid any ammonia appearing? I've had many tanks over the years and often added a couple more fish to an existing tank without problem. Are you saying that any increase in fish in a cycled tank will cause ammonia to spike?

Also, I have hard water. Ph is 7.5.

I'm taking steps to rid the tank of the trace of nitrites....asap.

Mollies are very hardy fish, I'm told by my lfs.

I won't net them. They're pretty easy to catch with a large cup that I have.

Thank you for caring so much!

I do care, I really honestly do. I love my fish, and all fish. Over the years I have learned how incredibly complex fish are, compared to any land animal. Their aquatic environment is very closely intertwined, so to speak, to the fish physiology and metabolism.

The pH 7.5 is OK, though for mollies permanently I would want it maybe higher, but it is the GH that really matters as they need the calcium and magnesium in the water.

Mollies are not hardy, believe me. Among livebearers, they are the most sensitive when it comes to water parameters (GH, KH, pH and temperature). It is interesting how often they are "first fish," and they rarely survive more than a few months at best.

Now, on adding fish and ammonia, etc. Once you have cycled an aquarium, there is a colony of Nitrosomonas sp. (the ammonia gobblers) and Nitrospira sp. (the nitrite gobblers) bacteria on surfaces. Most will be in the filter initially, but they do colonize other surfaces. They will multiply in proportion to the available food (ammonia and nitrite respectively). Once they are there, if the ammonia/nitrite should lessen, they do not die (as some mistakenly believe) but go into a sort of suspended state, and they can remain like this for months. There are factors that affect this, from pH to temperature to adverse conditions (bleach as an obvious example would kill them). When we add more fish, they become active; if there are insufficient of them, they multiply by binary division. Nitrosomonas take roughly 12+ hours, while Nitrospira can take up to 32 hours to divide. Each bacterium can divide into two bacteria, so this is pretty significant once they get going.

You can overload them with too many fish, depending upon various factors, and water volume is important; the larger the tank, the less chance this will occur. Live plants help, especially fast growers, of which floating are the very best. Floating plants are ammonia sinks, taking up a considerable amount. Plants also do this faster than the bacteria. So, generally, adding more fish shouldn't cause problems.

Byron.

 

[I_Smell_Fish]

I do care, I really honestly do. I love my fish, and all fish. Over the years I have learned how incredibly complex fish are, compared to any land animal. Their aquatic environment is very closely intertwined, so to speak, to the fish physiology and metabolism.

The pH 7.5 is OK, though for mollies permanently I would want it maybe higher, but it is the GH that really matters as they need the calcium and magnesium in the water.

Mollies are not hardy, believe me. Among livebearers, they are the most sensitive when it comes to water parameters (GH, KH, pH and temperature). It is interesting how often they are "first fish," and they rarely survive more than a few months at best.

Now, on adding fish and ammonia, etc. Once you have cycled an aquarium, there is a colony of Nitrosomonas sp. (the ammonia gobblers) and Nitrospira sp. (the nitrite gobblers) bacteria on surfaces. Most will be in the filter initially, but they do colonize other surfaces. They will multiply in proportion to the available food (ammonia and nitrite respectively). Once they are there, if the ammonia/nitrite should lessen, they do not die (as some mistakenly believe) but go into a sort of suspended state, and they can remain like this for months. There are factors that affect this, from pH to temperature to adverse conditions (bleach as an obvious example would kill them). When we add more fish, they become active; if there are insufficient of them, they multiply by binary division. Nitrosomonas take roughly 12+ hours, while Nitrospira can take up to 32 hours to divide. Each bacterium can divide into two bacteria, so this is pretty significant once they get going.

You can overload them with too many fish, depending upon various factors, and water volume is important; the larger the tank, the less chance this will occur. Live plants help, especially fast growers, of which floating are the very best. Floating plants are ammonia sinks, taking up a considerable amount. Plants also do this faster than the bacteria. So, generally, adding more fish shouldn't cause problems.

Byron.

Thank you. I really do care too. I didn't know these things about mollies. I dote on my fish, nothing is too good for them and nothing is too much trouble if it will make them happier. I even have fish anesthesia to euthanize dying fish with so they don't have to suffer before dying. My male betta just died. He was in this 15 gallon tank. I've been very sad since. I'm still going to call the tank "Bill's Tank" in memory. I'm sappy, just not as knowledgeable as you.

Thank you again!

 

[I_Smell_Fish]

Drats. I chose these mollies because I thought they were ordinary and I wouldn't have a hard time returning them to the store when the tank was ready for the female bettas, but I was wrong. These two girls hang out together all the time, in tandem. The diminutive one has cute little bug-eyes with a touch of what looks like neon in the eyes. I don't want to give them back, but I've been wanting a sorority for two long years and I'm finally on the verge of having it. I don't know what to do. I suppose I could start a second tank for the mollies, but it would have to be so big and our house is tiny and bursting with our current tanks. I dunno.... I messed up. I thought I had such a good idea....sigh.