Thought tank had cycled, now not so sure

[paul.o]

I have a red sea max nano 75L, I used old dried out live rock for the scape and sand substrate, my own RO water so zero tds.

Plan was to do a fishless cycle using seachem stability, the tank was started cycling on the 6th sept, it looked like it was cycling ok so on the 15th sept to check I dosed 2ppm ammonia, 24 hrs later ammonia was 2ppm and 0.5ppm nitrite so it looked like it wasn't cycled fully.

To give it a bump I decided to try fritz turbo start so dosed that along with ammonia on the 20th sept, by the 30th sept tank looked cycled with 0 ammonia & 0 nitrite so fast forward to yesterday I wanted to be sure it's cycled before adding fish, I dosed 2ppm ammonia and checked levels today, 1ppm ammonia & 1ppm nitrite. Another odd thing is that a week ago I did a big water change to bring the nitrate down from 40ppm to 5ppm, today the nitrate is 50ppm so not sure what's going on really, any thoughts?

 

[Spare time]

Nitrite can interfere with nitrate tests. I wouldn't test nitrate until nitrite is gone. Once ammonia and nitrite are gone, you can add a fish or whatever. I'd recommend buying a pre-quarentined fish if you are just starting and don't want to have a QT tank.

 

[paul.o]

Thanks I only tested nitrate as I was sure it had cycled, I am planning on getting a chunk of live rock and some sand from an established tank to give it a kick start

 

[fishyjoes]

If you added fritz turbo start you're done. Stop adding ammonia, wait for the ammonia to go down or water change it away and you can add a fish

 

[paul.o]

That's the thing, the ammonia did go to zero along with nitrate within 5 days of adding Fritz, about 2 weeks later I tested it with ammonia and it was still there 24 HR later, that's the bit I don't get

 

[Dbichler]

You were cycled after the 5 day of fritz. Check your nitrates again and do a water change to bring them down if necessary. You no longer need to test ammonia or nitrite. Add a fish and begin.

 

[Troylee]

Let me guess you’re using an api test kit? Your tank is cycled and fine! Stop adding stuff and enjoy your tank.. api will always say you have ammonia and it’s a false reading cause those tests are trash.

 

[taricha]

That's the thing, the ammonia did go to zero along with nitrate within 5 days of adding Fritz, about 2 weeks later I tested it with ammonia and it was still there 24 HR later, that's the bit I don't get

You added 2ppm ammonia and about half of it was gone The next day. That's plenty fast to keep up with a modest livestock load.
The production of nitrite interferes with nitrate tests and can make it look much higher than it is.

wanted to be sure it's cycled before adding fish, I dosed 2ppm ammonia and checked levels today, 1ppm ammonia & 1ppm nitrite. Another odd thing is that a week ago I did a big water change to bring the nitrate down from 40ppm to 5ppm, today the nitrate is 50ppm so not sure what's going on really, any thoughts?

In short, everything is good and working as you would hope after cycling with bacteria.

 

[paul.o]

indeed on checking ammonia today it is zero, still 1ppm nitrite so i'll do a water change to reduce it. plan was to stock a pair of clowns and a goby, collecting the goby this weekend and the clowns the following weekend.

 

[paul.o]

Let me guess you’re using an api test kit? Your tank is cycled and fine! Stop adding stuff and enjoy your tank.. api will always say you have ammonia and it’s a false reading cause those tests are trash.

yep they are api, it's just the nitrite that i'm bothered about as a week ago it was zero, now its 1ppm, going to do a water change to bring it down before putting a fish in.

 

[Troylee]

yep they are api, it's just the nitrite that i'm bothered about as a week ago it was zero, now its 1ppm, going to do a water change to bring it down before putting a fish in.

Again it’s an api test… lol. Anywho nitrites are harmless in marine animals “unlike fresh water” so they don’t matter and shouldn’t be tested for. If you really had nitrite your nitrates would be through the roof as it would give more false readings.

 

[brclark82]

You’re overthinking this…

first nitrite isn’t harmful to marine fish that is a freshwater thing,

second the denitrifying cycle takes a little longer to build up than the nitrifying,

the only reason to even test for nitrite in a marine aquarium is if you want to see if your cycle has started or to see if your early nitrate tests are accurate,

third unless you are going to be very heavily bioloading this tank from day one you will never have to deal with you tank being able to convert 2ppm ammonia until it has had enough time to build up that level of nitrifying bacteria

Stop adding ammonia, add some fish and start feeding them. You can keep testing for nitrite if you would like but only so that you will be able to tell when your nitrate tested are accurate, don’t worry about the levels.

 

[PotatoPig]

yesterday I wanted to be sure it's cycled before adding fish, I dosed 2ppm ammonia and checked levels today, 1ppm ammonia & 1ppm nitrite. Another odd thing is that a week ago I did a big water change to bring the nitrate down from 40ppm to 5ppm, today the nitrate is 50ppm so not sure what's going on really, any thoughts?

The ammonia you added yesterday is being converted by bacteria to Nitrites and then Nitrates, which is why your Nitrates have gone back up. This means you’re cycled.

Nitrates are typically very slowly removed by bacteria, but also aren’t toxic in marine tanks at any level you’ll realistically reach. They’ll mostly hang about unless you either do a lot of water changes or have corals/algae/macro algae in the tank that’ll absorb them as food.

 

[jda]

My only caution with dried out live rock is that there is likely organics on that rock that will start to break down. When they start, it can be an avalanche. If this rock was not cleaned or anything, then a new tank which has the ability to process a bit of fish waste, but truly is not cycled all the way, could get overwhelmed.

Nobody can really know what is going on with the rock without seeing it or maybe even smelling it now that it is wet again. If you can shake a rock and some stuff comes off, that it usually decomposition.

Contrary to what some self-proclaimed cycle experts want to make you believe, there is no one-size-fits all answer for this and cases reusing media with dead organics is a huge wildcard.

Put your nitrate test kit away. Just meaningless right now. Come back to it when the tank is starting to get film algae or matting bacteria.

 

[paul.o]

My only caution with dried out live rock is that there is likely organics on that rock that will start to break down. When they start, it can be an avalanche. If this rock was not cleaned or anything, then a new tank which has the ability to process a bit of fish waste, but truly is not cycled all the way, could get overwhelmed.

Nobody can really know what is going on with the rock without seeing it or maybe even smelling it now that it is wet again. If you can shake a rock and some stuff comes off, that it usually decomposition.

Contrary to what some self-proclaimed cycle experts want to make you believe, there is no one-size-fits all answer for this and cases reusing media with dead organics is a huge wildcard.

Put your nitrate test kit away. Just meaningless right now. Come back to it when the tank is starting to get film algae or matting bacteria.

The rock was scrubbed and then soaked in RO for a month with weekly 100% water changes so while i can't say it definitely isn't leaching anything hopefully it won't be a lot.

 

[jda]

It will certainly release bound phosphate - this is more like leeching, but not exactly, since it is a reversible bind.

The water and bacteria over time can get to places where you could not. The cleaning will help a lot, but don't discount the possibility of an ammonia spike that your tank might not be able to handle super quick if those organics start to decompose. I would tend to trust a test kit in these situations rather than count days.

Lower levels are nitrite are no issue for fish, but they can harm inverts and higher levels can harm anything.

You just have to pay a bit more attention than some other folks.

 

[brandon429]

The tank is cycled agreed, and the test stated readings are all over the place for ammonia just like they usually are with non digital kits.

he’s stated there’s still 1 ppm ammonia, how is it that just for this round the cycle umps agree he’s ready

I just saw posts on other threads where 1 ppm leftover was stated as dead bottle bac and the keeper was told to buy more, until ammonia was zero

what are the non test kit markers stated here that’s allowing the consensus that he’s ready (which I agree with)

it’s usually like pulling teeth to get people to ignore what api says , why the immediate dismissal here today?

updated cycling science wants to know how the cycle umpires here validated a cycle while ignoring high stated levels of ammonia from api, I thought that test kit was recently deemed pretty accurate per chemistry forum posts

knowing when to disavow test kit readings and when to believe them without question is a big deal in cycle troubleshoot science, why ignore the stated levels here? It’s been 24 hours since his last triple dose, unresolved as stated?

 

[brclark82]

@brandon429 His tank has already taken 2.0ppm to zero and then most recently from 2.0 to 1.0 in just 24hours (based on api tests), if the tank is capable of that then in my opinion it’s certainly cycled enough to be ready for fish

 

[brandon429]

Why ignore the remaining 1 ppm, isn’t that a stall (the rules said ammonia must be zero on 100% of cycle articles)

if the cycle wasn’t stalled, wouldn’t this third load dose be neutralized overnight

I can’t figure out from searches compared to this post if we are supposed to believe api or not

what if the op reported 2 ppm ammonia, would that then trigger the umpires to agree its stalled and recommend a third bottle of bac? What rules allow us to ignore stated 1 ppm but take action at 1.5, or 2 ppm?


on tens of thousands of searchable threads, 1 ppm = dead bottle bac = cycle stalled

curious of what rules have changed where that’s no longer the case

 

[fishyjoes]

That's the thing, the ammonia did go to zero along with nitrate within 5 days of adding Fritz, about 2 weeks later I tested it with ammonia and it was still there 24 HR later, that's the bit I don't get

I don't know how much ammonia a fish generates, but 2 ppm is a lot - way more than one or two fish will generate.

I "pre-seeded" (fishless cycle) a tank until it could process 2ppm ammonia down to zero in 24 hours and was able to add 17 one to two inch sized fish all at once without an ammonia spike. That means that those 17 fish probably generated less than 2ppm ammonia per day.