Ammonia-0 Nitrites-0 Nitrates-0

[larochem595]

Ugh...
I have no idea what is going on with my tank...
This is a well established tank that has been going for about 7 plus years.
I added 2 otos to my tank and they had stringy poo. I treated with prazi and removed carbon filtration per directions. I did two rounds. Filter is now back in. The fish look great.
But now my tank is registering nothing
No ammonia, no nitrates and no nitrites. pH is a comfortable 7ish.
I went out and bought a new api nitrate test kit because I didn't really believe it....This really baffles my mind. I do a weekly 20% change. If I had killed the good bacteria, I'd expect that ammonia or nitrites would be high but they aren't.
I am stumped. The good news--my fish all look good... The string oto poo looks to be gone...nothing too concerning.

Why is my tank reading nothing though? I am monitoring readings daily at this point.

If any wise people have encountered this, let me know.

Thanks,
Michelle

 

[Andy Sager]

Did you happen to take any readings before you started the treatment? When you say you removed the carbon filtration, did you mean just the carbon or the whole filtering system?
We need some more info as to how the tank is set up, (i.e. planted/unplanted) supplements used, substrate, types of filtering materials, tank size to bioload, etc. to better figure out what happened or what's happening.

 

[larochem595]

Before I started treatment, it nitrates were usually around 10 or 20. (I didn't typically always do ammonia, pH or nitrites because it was a long term stable tank. Nothing ever fluctuated.) In late November, my town did something funky with my water supply...had a sudden pH drop in my city water and lost one of my cories. I was sad, had these guys a Long time. Long story short, I got things back to normal--the usual nitrates around 10-20.

Fast forward to the addition of my otos during Christmas time: added two otos. They had stringy poo (I am not sure if they were overeating on algae in my tank or if they had a parasite.) I used the Praziquantel as described above.
I left my mechanical sponge filter in and just took out my floss pouch with carbon in it. (I only filter with carbon and mechanical sponge.) It's a hang on back filter.

It's a 10 g unplanted tank (with a little bit of hornwort.) At the moment, I have 2 cories and 2 otos (who think they are cories, they sometimes like to hang with them.) KH typically runs around 4 and GH I honestly haven't done in some time... I use 2mL Replenish with my weekly 20% water change because my city water is usually soft.

I think that's everything....still baffles me that nitrates are nil.
I think I will hold off on this week's water change until I at least see something going on. Any other advice is welcome!

 

[Andy Sager]

Before I started treatment, it nitrates were usually around 10 or 20. (I didn't typically always do ammonia, pH or nitrites because it was a long term stable tank. Nothing ever fluctuated.) In late November, my town did something funky with my water supply...had a sudden pH drop in my city water and lost one of my cories. I was sad, had these guys a Long time. Long story short, I got things back to normal--the usual nitrates around 10-20.

Fast forward to the addition of my otos during Christmas time: added two otos. They had stringy poo (I am not sure if they were overeating on algae in my tank or if they had a parasite.) I used the Praziquantel as described above.
I left my mechanical sponge filter in and just took out my floss pouch with carbon in it. (I only filter with carbon and mechanical sponge.) It's a hang on back filter.

It's a 10 g unplanted tank (with a little bit of hornwort.) At the moment, I have 2 cories and 2 otos (who think they are cories, they sometimes like to hang with them.) KH typically runs around 4 and GH I honestly haven't done in some time... I use 2mL Replenish with my weekly 20% water change because my city water is usually soft.

I think that's everything....still baffles me that nitrates are nil.
I think I will hold off on this week's water change until I at least see something going on. Any other advice is welcome!

Hornwort is actually a big consumer of Nitrates so that may have had some effect. A lower amount of food being fed during treatment combined with a big nitrate consumer may be your answer.
Check your tap water to see if there are any nitrates in there. If there are, more investigation needs to be done.

Also, make sure you really shake up the nitrate reagents before testing. I've found the Nitrate ones in the API tests are more finicky than the other regents.

 

[larochem595]

Hornwort is actually a big consumer of Nitrates so that may have had some effect. A lower amount of food being fed during treatment combined with a big nitrate consumer may be your answer.
Check your tap water to see if there are any nitrates in there. If there are, more investigation needs to be done.

Also, make sure you really shake up the nitrate reagents before testing. I've found the Nitrate ones in the API tests are more finicky than the other regents.

Never thought to check my tap water nitrates. I did a side by side comparison. Both look zero and pretty identical.
I fear that I screwed up my tank's cycle when I pulled out my carbon filter for a chunk of time. But I don't see ammonia.

 

[Andy Sager]

Never thought to check my tap water nitrates. I did a side by side comparison. Both look zero and pretty identical.
I fear that I screwed up my tank's cycle when I pulled out my carbon filter for a chunk of time. But I don't see ammonia.

But I don't see ammonia.

...
YET!!! ?? How many fish are in the tank before adding the Ottos?
You should still have nitrifying bacteria in the tank as well as the filter sponge as long as the filter was running unless the medication you used had some kind of antibiotic that would suppress the bacteria bed.

 

[Colin_T]

How many fish are in the tank?
How big is the tank?
How often do you feed the fish?
Can you post a picture of the entire tank so we can see the plant to water/ fish ratio?

If you only have a few fish in the tank, and you have a lot of plants, the plants will use any ammonia, nitrite and nitrate and keep the levels low.

Your tap water might have had 10-20ppm nitrate before this and the water company has found a new source that doesn't have nitrates.

Removing the carbon filter won't cause a crash in the filter cycle unless you turned the filter off and left the good bacteria to die in the sponge in the filter.

You don't normally need carbon in a filter unless you have heavy metals or chemicals in the water. If that is the case, then you should filter the water through carbon before using that water in the aquarium. If you want to use carbon, that is fine but it's not normally necessary in most tanks.

The new test kit could be dodgy. Maybe take a sample of tank water to a pet shop and get them to test it. Take your test kits and test the same sample of water at the same time. See if the results are the same?

 

[larochem595]

...
YET!!! ?? How many fish are in the tank before adding the Ottos?
You should still have nitrifying bacteria in the tank as well as the filter sponge as long as the filter was running unless the medication you used had some kind of antibiotic that would suppress the bacteria bed.

Two fish were in there prior--the two cories.

I agree that there should still be nitrifying bacteria, especially if the tank was well established and I left the sponge filter in.
No antibiotics were ever used...just the Praziquantel.

 

[larochem595]

How many fish are in the tank?
How big is the tank?
How often do you feed the fish?
Can you post a picture of the entire tank so we can see the plant to water/ fish ratio?

If you only have a few fish in the tank, and you have a lot of plants, the plants will use any ammonia, nitrite and nitrate and keep the levels low.

Your tap water might have had 10-20ppm nitrate before this and the water company has found a new source that doesn't have nitrates.

Removing the carbon filter won't cause a crash in the filter cycle unless you turned the filter off and left the good bacteria to die in the sponge in the filter.

You don't normally need carbon in a filter unless you have heavy metals or chemicals in the water. If that is the case, then you should filter the water through carbon before using that water in the aquarium. If you want to use carbon, that is fine but it's not normally necessary in most tanks.

The new test kit could be dodgy. Maybe take a sample of tank water to a pet shop and get them to test it. Take your test kits and test the same sample of water at the same time. See if the results are the same?

Check out my previous replies...

The filter was on, just removed the carbon pouch and left my sponge in.
I feed once a day, alternating between a Seachem tropical flake and algae tabs for the otos.
Very little plant in the tank...just a tiny amount of hornwort that you can see above.

 

[Andy Sager]

Check out my previous replies...

The filter was on, just removed the carbon pouch and left my sponge in.
I feed once a day, alternating between a Seachem tropical flake and algae tabs for the otos.
Very little plant in the tank...just a tiny amount of hornwort that you can see above.

Things to consider:
Your bioload is small for the tank so no ammonia is not really surprising. An ammonia reading at this point would probably come from the food you feed more than the fish. Keep feeding the amount you currently feed as it doesn't seem to be affecting anything.

Since there is a small amount of ammonia being produced by your fish and you have an established filter and you have a nitrate consuming plant in the tank, 0 nitrates is not too surprising as well. You can check with your water company to see if there has been a change in the nitrate level in the water from before the November incident. I have a sneaking suspicion there has been.
Your routine water changes are also diluting the nitrate level so that can also account for the 0 nitrate.

At this point, I would just check the water every 5-7 days just to see if there are any changes and definitely check the water daily if you add more fish. Since you have a low bioload, you have a small biological bed so any new fish will require the bed to grow which can take time. How much time all depends on how much you add at one time. Small amounts and you may not see any differences at all.

 

[larochem595]

Things to consider:
Your bioload is small for the tank so no ammonia is not really surprising. An ammonia reading at this point would probably come from the food you feed more than the fish. Keep feeding the amount you currently feed as it doesn't seem to be affecting anything.

Since there is a small amount of ammonia being produced by your fish and you have an established filter and you have a nitrate consuming plant in the tank, 0 nitrates is not too surprising as well. You can check with your water company to see if there has been a change in the nitrate level in the water from before the November incident. I have a sneaking suspicion there has been.
Your routine water changes are also diluting the nitrate level so that can also account for the 0 nitrate.

At this point, I would just check the water every 5-7 days just to see if there are any changes and definitely check the water daily if you add more fish. Since you have a low bioload, you have a small biological bed so any new fish will require the bed to grow which can take time. How much time all depends on how much you add at one time. Small amounts and you may not see any differences at all.

Thank you for your help, Andy and Aiken
I think there was definitely a change in my water supply at some point....it definitely stinks when that sort of thing happens but I suppose it's a part of the hobby.... I rent an apartment so I am kind of stuck with what I have.

I think my plan of attack will be to let my tank get a bit "dirtier" before I attempt another change. I will keep an eye on ammonia and nitrates. Bottom line is that my fish look happy and healthy.

I'll let you all know if anything interesting happens.

Thank you all.

 

[Colin_T]

You need a picture on the back and some floating plants to help the fish feel more secure. Then they will come out more during the day. Water Sprite (Ceratopteris thalictroides/ cornuta) is one of the better floating plants and can be planted in the gravel as well.

Otocinclus catfish don't normally do well in new tanks. They do best in tanks with a layer of algae and biofilm (slime on the glass) so they have something to eat. You can increase the lighting times by a couple of hours a day to encourage algae to grow. The biofilm will build up over the next few months.

I doubt there's enough hornwort to use all the ammonia but you do only have 4 small fish and Otocinclus don't produce a lot of ammonia. It could be a combination of factors including a new water source (without nitrates), low bioload from the fish, and the hornwort is working overtime.

Just monitor things over the next few weeks and check with the water company to see if they got a new water source.

------------------

When you treated with Praziquantel, you did 2 rounds. How exactly did you do the treatments (ie: did you add a dose, wait a week and then add a second dose)?

Normally with deworming fish you treat once a week for 3 or 4 doses and that usually does the job. You do a 75% water change and gravel clean the substrate 24-48 hours later to remove any expelled worms and worm eggs in the substrate. You should also give the filter a clean to remove bits of worm from that.

Praziquantel treats tapeworm and gill flukes. If the fish have round/ thread worms, you will need Levamisole or Flubendazole. And again, treat once a week for 3 or 4 weeks. Generally 3 doses in tropical tanks and 4 doses in cool/ cold water tanks.

 

[larochem595]

You need a picture on the back and some floating plants to help the fish feel more secure. Then they will come out more during the day. Water Sprite (Ceratopteris thalictroides/ cornuta) is one of the better floating plants and can be planted in the gravel as well.

Otocinclus catfish don't normally do well in new tanks. They do best in tanks with a layer of algae and biofilm (slime on the glass) so they have something to eat. You can increase the lighting times by a couple of hours a day to encourage algae to grow. The biofilm will build up over the next few months.

I doubt there's enough hornwort to use all the ammonia but you do only have 4 small fish and Otocinclus don't produce a lot of ammonia. It could be a combination of factors including a new water source (without nitrates), low bioload from the fish, and the hornwort is working overtime.

Just monitor things over the next few weeks check with the water company to see if they got a new water source.

------------------

When you treated with Praziquantel, you did 2 rounds. How exactly did you do the treatments (ie: did you add a dose, wait a week and then add a second dose)?

Normally with deworming fish you treat once a week for 3 or 4 doses and that usually does the job. You do a 75% water change and gravel clean the substrate 24-48 hours later to remove any expelled worms and worm eggs in the substrate. You should also give the filter a clean to remove bits of worm from that.

Praziquantel treats tapeworm and gill flukes. If the fish have round/ thread worms, you will need Levamisole or Flubendazole. And again, treat once a week for 3 or 4 weeks. Generally 3 doses in tropical tanks and 4 doses in cool/ cold water tanks.

Thanks for the plant recommendation....I'd eventually like to get back to plants. I fear that nitrates are too low right now to add them in but will definitely keep that in mind.

I used prazi once a week for two weeks, following water changes and thorough vacuuming.

So, the tank is definitely not a new tank. It's been going for 7 plus years and there was plenty of algae (green spot, brown diatom and a tiny bit of hair algae.) They didn't much care for the green spot but everything else is gone. (I love these little scrubbers ?.) I'm not terribly sold on the idea of having worms. I am wondering out loud--perhaps adding the otos into a tank which had a bunch of algae and biofilm might have caused the stringy poo because they had high intake? It seems to have resolved so am just going to keep an eye on it.

 

[Colin_T]

If they eat lots of food they do lots of poop and if its coloured (green, brown, black) it's fine. But if they do stringy white poop, that's an intestinal issue (worms, protozoan or bacterial infection).

Plants prefer ammonia to nitrate so as long as there are fish in the tank and you feed them, you give the plants enough ammonia/ nitrite/ nitrate to be happy.

I just used an iron based liquid plant fertiliser called Sera Florena and never bothered adding anything else. My plants did great and I had no nitrates in the tanks.

 

[Andy Sager]

Have to agree with Colin on the Poop details. If it had color, it was normal. If it was white, more likely a worm or intestinal parasite. Bottom fish are just more prone to having intestinal worms because they are closer to the source and not always active swimmers.