Weird Cycle

[Ozzi-reef]

Hi Folks.

You might have seen my thread in the intro forum, but to briefly recap, I have a 100g tub in an environment controlled box on my balcony in which I’m cycling 400+lbs of rock (350 of which was dry and 50 live from an old tank).
Anyway I kicked things off two weeks ago. Did the dead shrimp (we call them prawns btw) and Ammonia peaked at around 8ppm a few days ago. Two days ago Nitrite hit over 6ppm and Nitrate at least 30ppm.
All pretty normal so far, right? I measured today and Ammonia was zero (great, earlier than expected), Nitrite zero (wow that was a quick peak but ok), but Nitrates (which I expected so see well over 50ppm) was ZERO.
I’m trying to understand this result and the only thing I can think of is that the massive 1:1 water to rock ratio is the reason. But even so could the anaerobic bacteria that process Nitrate into Nitrogen really have cleared the Nitrate that fast? If so it says a lot for the good ol Berlin method and I’ll be putting all the rock in up coming Red Sea P650 build - the fish might be a bit cramped, but dang they’ll have nice water [emoji23]

 

[road_runner]

If you add a fish you will start seeing no3.
My guess is that since you system is so big, a dead shrimp will not be enough to trigger the nitrafying bacteria populations and sustain its growth.
Either add a fish, or add Dr. Tim bacteria so you kickstart the cycle.
Bacteria also need sustained food for it to thrive.

 

[BeejReef]

Won't pretend to know the answer, but the Nitrate went somewhere... right? It's not like you never had any.

I would have expected to see a higher end Nitrate reading with ammonia as high as 8.

The other thing that interests me is that your cycling setup appears to have a top. Is that so? That may give you a lower oxygen environment than in your typical tank and facilitate the anaerobic denitrification everyone talks about like cold fusion.

 

[brandon429]

this fits all the descriptions in the microbiology of cycling thread, its behaving normally

the specific reasons are you hydrated the sample, added bacteria and feed, and waited close to the 20 day mark which literally all cycling charts begin to show the downslope of nitrite, tied to the downslope of ammonia. however a tester reads in the interim, known to vary vastly across testers to the point testing for the big three is nearly useless, does not matter. clearly you just demonstrated no ammonia spikes kill nitrifiers.

Your system would've cycled even without the shimp added, this just sped things up nicely, quicker than the charts show. this cycle is behaving normally

 

[road_runner]

this fits all the descriptions in the microbiology of cycling thread, its behaving normally

the specific reasons are you hydrated the sample, added bacteria and feed, and waited close to the 20 day mark which literally all cycling charts begin to show the downslope of nitrite, tied to the downslope of ammonia. however a tester reads in the interim, known to vary vastly across testers to the point testing for the big three is nearly useless, does not matter. clearly you just demonstrated no ammonia spikes kill nitrifiers.

Your system would've cycled even without the shimp added, this just sped things up nicely, quicker than the charts show. this cycle is behaving normally

+1 to that.
This method of cycling will take time. Either you add some bacteria or add one fish. If there is no food source for the bacteria it will die eventually and cycle will not continue.

 

[brandon429]

hey also just read there's real live rock too, that alone is such a powerful/scrub based on surface area that what the dry rocks are doing can't be measured if they're grouped in the same water. We have to wait on submersion timing now to call that portion cycled, at 30 days max by association (faster, this is the safe no test sub time)

I had missed that live rock component...its so massive it also has nearly permanent stores of feed/organics for bac

 

[brandon429]

if you want to get fancy for us

peel off a few lbs of the dry portion that sat with the live this long, I bet its ready on its own


put it in a paint bucket or similar model, dose a little ammonia

in 24 hours I bet that rock alone oxidizes half or one ppm, proving they're cycled too

to get your tester above to prove/disprove the sep live rocks are ready: after you move them to a bucket of clean circulating saltwater, test with that ammonia kit and note the color. whatever it reads = zero, bc this is all new water w no dead shrimp and just bare rocks that have been wet, that's zero ammonia if the new water is mixed up early and balanced.

dose liquid ammonia, dr tims until the tester changes barely, you aren't trying to get to 2ppm and back down, you're making your tester go from calibrated zero to some minor color change only, then stop adding the liquid ammonia.

retest in 24, its back to calibrated zero. that's the only way to get ammonia testers to perform correctly, if we're testing wastewater on them and mixed metabolites, the readings will be all over the place between the big 3...this is why we do ammonia + time only in updated cycling threads, then all cycles behave exactly the same.

 

[bluprntguy]

If you have live rock then the bacteria that eliminates nitrates is already established and simply consumed the nitrates. That's quite a bit of rock in a relatively small amount of water, so it's not surprising that it was able to eliminate the nitrates.

I'd say you are good to move the rock to your tank and slowly start to add fish...

 

[Brew12]

A one time dose of 8ppm ammonia (your max reported reading) would generate almost 29ppm nitrate. If this was clean dry rock that is what you should have expected to see.

Judging from your pictures it appears that you have some algae growing on your rock. This likely consumed some of your ammonia directly and also took up the nitrate. I would have no concerns putting this in an aquarium and adding fish.

 

[road_runner]

A one time dose of 8ppm ammonia (your max reported reading) would generate almost 29ppm nitrate. If this was clean dry rock that is what you should have expected to see.

Judging from your pictures it appears that you have some algae growing on your rock. This likely consumed some of your ammonia directly and also took up the nitrate. I would have no concerns putting this in an aquarium and adding fish.

Agreed with brew. I would add a fish and give it time. Feeding the fish and the fish waste will build up the biological filtration stronger

 

[Ozzi-reef]

Won't pretend to know the answer, but the Nitrate went somewhere... right? It's not like you never had any.

I would have expected to see a higher end Nitrate reading with ammonia as high as 8.

The other thing that interests me is that your cycling setup appears to have a top. Is that so? That may give you a lower oxygen environment than in your typical tank and facilitate the anaerobic denitrification everyone talks about like cold fusion.

That’s a really interesting thought. It might be a factor somehow. There is indeed a heavy wood lid, but the are a few 2 inch holes in the side and also a recently added ventilation fan.

 

[Ozzi-reef]

Agreed with brew. I would add a fish and give it time. Feeding the fish and the fish waste will build up the biological filtration stronger

Not keen to add fish to the tub - I’ll never get the buggers out again - at least not till I transfer all the rock to the tank (which is still months away). I was planning to just dose daily ammonia to keep the rock happy and maybe some clean-up crew.
But if you think that fish is the only way then happy to hear any suggestions of inexpensive species who would be happy in a 4’ x 24” x 24” maze of rock.

 

[brandon429]

in no way do you have to add feed to a hydrated system to keep bac fed. We have 3 year fallow test threads(no feed 36 mos, instantly passes a 2 ppm oxi test)
bac are always, always accessing feed.

adding extra feed is phosphate loading your system unnecessarily. we cannot starve an active hydrated nitrifier colony kept in a vectoring, contaminated home setting, they're perpetual if merely kept wet. it literally takes a microbiology lab + practices to starve wet bac

 

[Ozzi-reef]

Excellent feedback folks. I do understand that the rock processed both the Ammonia and Nitrite. But my confusion is what happened to the Nitrate. It can’t have been taken by the little bit of algae on the top layer of rocks. Had to be the rocks themselves. The thing is I thought (might be wrong) that the anaerobic bacteria that eat Nitrate take the longest to populate the deep rock sections - is two weeks enough or was it the 50lbs of older partly live rock that did the trick?

 

[road_runner]

Not keen to add fish to the tub - I’ll never get the buggers out again - at least not till I transfer all the rock to the tank (which is still months away). I was planning to just dose daily ammonia to keep the rock happy and maybe some clean-up crew.
But if you think that fish is the only way then happy to hear any suggestions of inexpensive species who would be happy in a 4’ x 24” x 24” maze of rock.

Then just patience.

 

[brandon429]

the nitrate is too variable to detect reliably, therefore we don't factor it in a cycle. I know the old articles did, but we're just updating them that's all ha

you listed actions like denitrification which is possible with the live rock component, its always too many variables to worry about with nitrite and nitrate testing, so we've kicked them out of this thread below, in exchange for ammonia only + submersion time to call a cycle complete (and at that point, every tank is done by the same date like on google cycle charts)

If we get that updated info wrong, fish will die and we'll be flamed massively and thoroughly.

The microbiology of reef tank cycling.

You can skip your cycle. Ive been reefing online for twenty years and have never waited one second for a tank to cycle, because I buy rocks that are already cycled and move them home. Here's two: https://www.reef2reef.com/threads/octo-high-end-sps-skip-cycle-build.713256/...

www.reef2reef.com

 

[BeejReef]

That’s a really interesting thought. It might be a factor somehow. There is indeed a heavy wood lid, but the are a few 2 inch holes in the side and also a recently added ventilation fan.

No way of knowing really without running a control and experimental group. How cool would it be if you stumbled upon a method of preparing anaerobic rocks or sandbeds though

What would you call the process? "Ozzification," "Down-Undering?"

 

[sstanley223]

If it was me I'd keep feeding it every few days and watch the numbers.

 

[Brew12]

It can’t have been taken by the little bit of algae on the top layer of rocks. Had to be the rocks themselves.

I disagree with this. I feel it has been taken out by that little bit of algae. You don't have a huge water volume and you didn't add a large ammonia source. It wouldn't take much algae at all to consume the ammonia and nitrate from a single prawn with a ammonia peak of 8ppm

 

[Ozzi-reef]

I'm thinking that most of the ammonia did not come from the prawn but rather the dry rock. I should have clarified that it's not man-made or mined rock but rather me spending the last few months collecting long dried once-live rock from various ex-reef tanks around Melbourne - that is how I slowly collected the quarter tonne worth. I could see that rock had loads dried organics on it (and probably even more inside). I also have a mountain of phosphate (10ppm+) but plan to run a Turbo L4 ATS in the tub (along with the blue reef light for coralline) as part of the maturation process

Another bit of interesting learning I got from this was the porosity of the rock we use. I put all the dry rock in the tub in one go (the small amount of live rock went in a few days later). After the rock went in I filled the tub to within an inch from the rim (using around 80-90g of NSW). In the morning I looked in the tub and nearly cried as the water level had dropped more than 8 inches (almost 1/3 the total depth). Obviously, my first thought was that I had a leak (the tub sits over the balcony drain, which would explain no water on the tiles) and would have to tear down and start again. But then it occurred to me that maybe the rock was acting like a sponge. I refilled the tub and the rock drank another 2 inches overnight, then one more inch across another few days, before finally stabilizing (no leak - phew!). So, by my rough calculations that rock now holds somewhere around 50 gallons of water - which really amazes me to think about.