Water Chemistry Questions

[Larry Little]

I have a 15 gallon tank that has been cycling for about 8 weeks. It seems to be stuck.

pH - 7.4
ammonia - 0.25
nitrite - 0.5
nitrate - 40

These readings have been stable for about 3 weeks. All of my other tanks run at about these readings with the exception of the nitrite; none of them show detectable nitrite.

My question is whether I can begin introducing livestock to this tank or not. It will be a nanotank with Pygmy cories, 2 trios of Endlers, and maybe 2 Otocinclus. I might go with a school of ember tetras rather than the Endlers.

I really need some advice on this. Thanks

 

[Aiken Drum]

How have you been cycling the tank?

 

[Larry Little]

Hi Aiken -- This is a tank I had set up for about 3+ years. I broke it down and cleaned everything; probably killed off the bacterial colony in the process. used a mixture of old and new substrate, old hardscape ( stones and wood), and returned plants (Vallisneria spiralis and added Java moss from another tank. There is a good colony of ramshorn snails. 2 sponge filters. I throw a little flake food in about once a week.

 

[Aiken Drum]

Thats not going to cycle a tank. There isn't enough ammonia going into it. You will have likely built up a little bacteria, but not enough to consider the tank cycled.

Your options are.

- Carry out a proper fishless cycle.
- Do a big water change, get a couple of fish, and complete your cycle as a fish in cycle.

 

[Joe_D]

It has been my experience that just adding a couple of fish is the best and quickest way to cycle a tank .

 

[Larry Little]

Doesn't adding a couple of fish simply sacrifice them to the ammonia and nitrites? I haven't done a cycle with fish in many years and have never had this problem before. My readings have on this tank are as follows:

pH _ 7.4 (stable reading for all of my tanks)
Ammonia _ 0.25-0.5 (For the last 4 weeks)
Nitrite _ 1.0 (went up from 0.5 last week; 2.0 the previous week)
Nitrate _ 80 (was around 40 for three weeks)

As I said, I have done fishless cycles for years and have never had a cycle stall out like this. I would have thought that the waste from snails would have been broken down to produce sufficient ammonia to complete the cycle.

 

[Aiken Drum]

Cycling with fish is fine.

What used to happen was people stocked a tank. When fish died they replaced them. When they stopped dying you where cycled. This is where fish in cycles get a bad rep and a lot of old poorly informed information is still out there.

Since those days knowledge of the nitrogen cycle has improved. Knowledge about water toxicity has improved. And testing has improved. This has all led to improved methods of fish in cycling. If done properly fish in cycling is perfectly safe.

We get a lot of traffic on the site with people having issues cycling tanks. By far more people have issues with fishless cycles than fish in. Almost every time issues with cycling are resolved when the switch is made to fish in cycle.

Your issues with your fishless cycle is to do with you not dosing sufficient ammonia. Its really not a fishless cycle at all as you are doing a fish in cycle, just with snails. They just dont have sufficient bioload to cycle the tank.

 

[Larry Little]

My plan is to keep a small school of pygmy cories (5-6) and either two trios of endler's livebearers or a small school of ember tetras (8). What fish would you begin with?

I was once considered to be an "expert" in aquarium keeping. Wrote my Master's paper reviewing the latest setup, maintenance, and display techniques for private and public aquaria. Worked as an aquarium keeper at the Tulsa Zoo for about 5 years. But... that was a long time ago and the hobby knowledge passed me by ( I stopped keeping aquariums for mor than 30 years). Knowledge and technology have changed greatly; I feel like a total novice at times.

The key back then was introducing organic matter (no fish) that could be broken down, producing ammonia in the process.

 

[Aiken Drum]

If you want to go with a fish in cycle i would do a number of big water changes. Get that nitrate down to about 10ppm. I would probably go with 2 or 3 of the livebearers or tetras to start with.

Do you know how to do a fish in cycle?

 

[Joe_D]

I will just add the once yout tank seems cycled with a couple of of fish, then add additional fish gradually until fully stocked. Just do not add all fish at once.

Check water parameters as you add more fish to make sure all is stable.

 

[Aiken Drum]

The key back then was introducing organic matter (no fish) that could be broken down, producing ammonia in the process.

Thats what a fishless cycle is. That organic matter can be fishfood, a cocktail shrimp, ammonia or my recommendation would be an aquarium specific ammonium chloride product. IMO ammonia/ ammonium chloride is the best source because it can be accurately dosed to the necessary concentration. How do you judge how much fish food to add to bring up ammonia sufficiently? Fish food goes mouldy and you would be dumping a lot of food in the tank over the weeks it takes to cycle a tank.

Personally im a fishless cycle advocate, but i know how it works and dont have unrealistic expectations on how long it takes. Fish in cycles are easier to understand and more consistently get you where you need to be. If you do as Joe_D says, stock lightly and add more fish gradually you will likely cycle a tank safely without knowing anything about cycling. You can make it as easy or complex as you want.

Your problem really is you are doing neither a fishless nor fish in cycle. You wasnt dosing ammonia to consider it a fishless cycle. And it took 8 weeks via your snails to get ammonia up to a level where your tank started to cycle.

 

[Larry Little]

Aiken, I know it takes a good while to do a fishless cycle. The reason for me to add food is to feed the herd of snails. I've used the snails instead of fish as they seem to be much more resistant to the adverse effects of ammonia and nitrite. Their waste gets broken down the same way as fish waste, just seems to take longer.

Back in my zoo days, we routinely did fishless cycling. This is my 7th tank to set up since I've been back in the hobby; it's the first time I've had one stall.

 

[Aiken Drum]

Like i said, its taken 8 weeks for the snails and their food to get ammonia up to a level where the tank is going to start to cycle. You need to get some more bioload in there and manage it through water changes.

Or remove all the snails and dose ammonia up to 2ppm and do a fishless cycle properly.

Carrying on how you are, you will still be waiting for the tank to cycle come christmas

 

[Andy Sager]

I will toss this into the mix ( from a fellow old timer ) :
If you are getting a nitrate reading, there is obviously bacteria in the tank to convert the nitrite to nitrate. Unless you are have that much nitrate in your source water, you might want to check your test chemicals to confirm they are accurate. ( Nitrate reagents tend to go bad the fastest. ) If you are using test strips, they tend to not be as accurate as liquid reagents.

Next would be when you are testing. Try testing first thing in the morning before adding any food.

"Stalled" cycles are usually due to a lack of bacteria to convert Nitrite to Nitrate. ( Low Ph values would prevent ammonia from being converted into nitrite so the cycle would not have started so it couldn't be "stalled". ) Considering that these do take some time to develop, it's understandable that people think the cycle stalled while in fact, it just hasn't completed it's natural course.

Here's a solution: If you have access to a cycled aquarium, adding some filtering material from that tank or a good squeeze of " dirty" water from an established sponge filter should solve your problem. ( The squeeze system is how I usually cycle tanks in my hatchery. ) The reproduction rate of nitrifying bacteria is quite rapid so there should be no ammonia or nitrite present within 48 hours.

The bottom line is your numbers don't really make sense to me which is why I question the testing materials. As you probably know ( or maybe forgot?) the nitrogen cycle, if drawn on a graph, would look like 2 camel humps. In order for nitrite and ammonia to be present at the same time, the ammonia would need to be on the downward curve while the nitrite would be on the upward curve. To have nitrate and ammonia present together would mean that the nitrate is not coming from the bacteria but more so from the source water. Over the years, the water systems have become much more complicated than in the past. Many water companies use Chloramine ( ammonia combined with chlorine to prevent chlorine evaporation) instead of just chlorine. You need to use something to break the ammonia/chlorine bond ( ie Seachem's PRIME or Kordon's Amquel) before adding any water. They also flush their systems with all kinds of chemicals that they didn't use in the past. Welcome to the new way to fish keeping.

Hope this helps.

 

[Larry Little]

Andy, thanks for the information. I have tested my source water a number of times since April, when the city water supply spiked ammonia up to 1.0 (no nitrites or nitrates). I killed a bunch of fish due to this; began adding Prime for any water changes or top-offs after that. Ammonia is back down to 0.25. My tank nitrates are reading high which tells me that the Nitrobacters are present and oxidizing nitrites. The nitrites likewise indicate the presence of Nitrosomonas. The City of Tulsa switched to using chloramines around 1983-84. I remember the panic for aquarium keepers at that time, including at the zoo.

The tank contains a ton of snails. I've successfully cycled 7 aquariums this way, including my 125, my 65, and my 40. Two of these cycles were on tanks that I broke down, thoroughly cleaned and reset. I don't think bio-load is insufficient as has been suggested.

 

[Andy Sager]

Andy, thanks for the information. I have tested my source water a number of times since April, when the city water supply spiked ammonia up to 1.0 (no nitrites or nitrates). I killed a bunch of fish due to this; began adding Prime for any water changes or top-offs after that. Ammonia is back down to 0.25. My tank nitrates are reading high which tells me that the Nitrobacters are present and oxidizing nitrites. The nitrites likewise indicate the presence of Nitrosomonas. The City of Tulsa switched to using chloramines around 1983-84. I remember the panic for aquarium keepers at that time, including at the zoo.

The tank contains a ton of snails. I've successfully cycled 7 aquariums this way, including my 125, my 65, and my 40. Two of these cycles were on tanks that I broke down, thoroughly cleaned and reset. I don't think bio-load is insufficient as has been suggested.

Yeah, when Florida switched to chloramine, a number of people and pet shops lost a lot of fish. There were even law suits by some people and it made the water companies have to send out warnings before doing any kind of excessive cleanings.
I agree that you can cycle an aquarium with any kind of ammonia source so using the snails is no big deal to me. The end result is always: The larger the ammonia source, the larger the bacteria bed that is created.
So, since you have nitrates and they are not coming from your source water, that should mean you have a bacteria bed.
That you are still getting an ammonia reading makes me think it's your test reagents. I'd have someone double check your test results.

On a side note, I used to sell some marine fish to the OK Zoo in the early-mid 80s. Was that you?