Cycle's almost finished - what now?

[Ioncewaslegend]

My cycle's going quickly and, after reading the guide up top, I still have a few questions:

1. What marks the cycle as "done"? I understand it's at least when ammonia and nitrite are 0 ppm, but is there anything else I need to wait for?

2. For the first water change, what's the best volume? I've gotten an average of ~20% based on other advice with some outliers, but I'm curious.

3. For mixed reefs is it better to add fish first or coral first?

4. I know coral doesn't affect the bioload quite like fish do, but how many frag(s) should be added at one time?

 

[Crabs McJones]

The best way to tell if your tank is cycled, is to increase ammonia to 2ppm, and if after 24 hours it's back to 0, you're good to go.
First water change will depend on how high nitrates got during your cycle. If they're on the lower end 10-15%
If they're on the higher end you could do 20-25% or a couple of smaller 10% spread out as to not affect the tanks chemistry.
I would start by adding a couple small fish. With fish you'll be able to tell right away if the tank is ready for more, corals not so much.
Add slowly, a couple frags here or there until the tank matures up.
Hope this helps

 

[Ioncewaslegend]

The best way to tell if your tank is cycled, is to increase ammonia to 2ppm, and if after 24 hours it's back to 0, you're good to go.
First water change will depend on how high nitrates got during your cycle. If they're on the lower end 10-15%
If they're on the higher end you could do 20-25% or a couple of smaller 10% spread out as to not affect the tanks chemistry.
I would start by adding a couple small fish. With fish you'll be able to tell right away if the tank is ready for more, corals not so much.
Add slowly, a couple frags here or there until the tank matures up.
Hope this helps

Thanks for your help, it does!

This might be hard to quantify but what would you call "the high end"? As of last night they're at 0.25/2/20 ppm (ammonia/nitrite/nitrate; after being at 2/0/0 48 hours prior).

 

[Crabs McJones]

Thanks for your help, it does!

This might be hard to quantify but what would you call "the high end"? As of last night they're at 0.25/2/20 ppm (ammonia/nitrite/nitrate; after being at 2/0/0 48 hours prior).

20PPM nitrate isn't too bad. 15-20% would be good

 

[Ioncewaslegend]

Thanks again! One additional followup question. You said that, "With fish you'll be able to tell right away if the tank is ready for more, corals not so much."

Is the "being able to tell if the tank is ready for more" just making sure ammonia/nitrite stay zeroed out?

 

[Crabs McJones]

Thanks again! One additional followup question. You said that, "With fish you'll be able to tell right away if the tank is ready for more, corals not so much."

Is the "being able to tell if the tank is ready for more" just making sure ammonia/nitrite stay zeroed out?

Yup. You should be able to tell with your test kits. But if you add a fish and see that it's suddenly lathargic, or hanging out in the top or bottom of the tank and breathing heavily, its a clue something is amiss

 

[Lasse]

0.25/2/20 ppm (ammonia/nitrite/nitrate; after being at 2/0/0 48 hours prior).

Your reading of 20 ppm NO3 is false and depends only on the 2 ppm NO2 reading. All NO3 test I know is constructed that way that they first convert all NO3 into NO2 and the test is reading the level of NO2 - not NO3 When you compare the colour with the chart - there is an "translation" and conversion factor in built in the charts colour and you read it as Nitrate (NO3) If there is - as in your case - already NO2 in the water - the reading will be false and you will read a much higher figure. No nitrate test - as I know - will give right result if there already is NO2 present in the sample. The conversion factor is normally between 50 and 100.

Normally - NO2 is not toxic to saltwater fish (but highly toxic in fresh water) and you can do as Crab mcjones suggest with a fish or two but I (of safety reason) normally not recommend to add fish if you have start a fishless cycle (adding ammonia by your self) if you read NO2 in your water. Normally I would use bottled bacteria ( nitrification bacteria) or other sources of nitrification bacteria (used gravel, used filter, soil or whatever) until I read 0 or near 0 in NO2. If you chose to add fish before NO2 reads 0 - be very careful with feeding - best is not to feed before NO2 is zero


Sincerely Lasse

 

[Ioncewaslegend]

Your reading of 20 ppm NO3 is false and depends only on the 2 ppm NO2 reading. All NO3 test I know is constructed that way that they first convert all NO3 into NO2 and the test is reading the level of NO2 - not NO3 When you compare the colour with the chart - there is an "translation" and conversion factor in built in the charts colour and you read it as Nitrate (NO3) If there is - as in your case - already NO2 in the water - the reading will be false and you will read a much higher figure. No nitrate test - as I know - will give right result if there already is NO2 present in the sample. The conversion factor is normally between 50 and 100.

Sincerely Lasse

Ah; thank you! I hadn't considered that, but it makes sense if it's similar to a horseradish peroxidase/etc reaction.

Actually, right after writing that sentence, I did some digging and found this from Cayman Chemical's nitrite/nitrate colorimetric assay:

So, assuming the test kit I'm using (API Saltwater Master) uses the same reaction mechanism—which it should, since my nitrite readout is purple—you're correct that I can get an accurate nitrite reading, but can't measure nitrate independently.

Thanks! I'll just measure ammonia and nitrite until both hit zero, THEN start measuring nitrate.

 

[Ioncewaslegend]

Yup. You should be able to tell with your test kits. But if you add a fish and see that it's suddenly lathargic, or hanging out in the top or bottom of the tank and breathing heavily, its a clue something is amiss

Oh, and (hopefully) last question, since I've been nerd sniped and doing a lot more digging this morning: I still haven't seen any sort of algae or anything else in the tank, and I've been cycling with lights off. Would it be a good idea to turn the lights on in the next couple days to start promoting that for nitrate cleanup/CUC food?

 

[Crabs McJones]

Oh, and (hopefully) last question, since I've been nerd sniped and doing a lot more digging this morning: I still haven't seen any sort of algae or anything else in the tank, and I've been cycling with lights off. Would it be a good idea to turn the lights on in the next couple days to start promoting that for nitrate cleanup/CUC food?

You can. I had my lights on during cycling. Just don't let the algae get too out of hand

 

[brandon429]

Can you find examples online where api or Red Sea ammonia showed .25 while it was truly zero? Curious how these test readings are trusted and remarked upon so quickly, no doubt about .25 though that reading cannot occur in reefing. Ammonia never ever holds at any level during a cycle, it never stalls. In a cycle, when 1-2 original ppm goes down at all, it goes to hundredths or thousandths ppm within hours and never rises to the tenths ppm again, without death causing a temp spike. It’s because rocks and sand are powerful surface area, activating them means ammonia goes down fast but only if you use an ammonia tester never shown to misread in thousands of posts.


Nitrite has no bearing on a cycle using updated cycle info. I’m aware older info required it’s measure, we are past that nowadays. All science progresses... I’ll bet your cycle is done in fact. How many days has it been underwater, and did you input bottle bac which cycles for bioload on the first day?

Before adding fish, choose your disease control protocol. See fish disease forums here for examples on skipping disease protocol. Updated cycling science (we have cycled 200 tanks on file recently, not a guess) has been amended to no nitrite needed to know, keep your tank clean and don’t allow it to self invade (uglies not allowed) and don’t add fish until you choose fallow/qt preps based on reading the fish disease forum two pages worth at least.

you should add simple starter corals and a clean up crew


if all cycles range so drastically, how do 500 tanks show up to marine conventions and start with full bioloads on time / old cycling is dead.

 

[lapin]

Time to QT some fish

 

[brandon429]

You always kill me with brevity

 

[Ioncewaslegend]

Can you find examples online where api or Red Sea ammonia showed .25 while it was truly zero? Curious how these test readings are trusted and remarked upon so quickly, no doubt about .25 though that reading cannot occur in reefing. Ammonia never ever holds at any level during a cycle, it never stalls. In a cycle, when 1-2 original ppm goes down at all, it goes to thousandths ppm within hours and never rises to the tenths again, without death causing a temp spike. Nitrite has no bearing on a cycle using updated cycle info. I’ll bet your cycle is done in fact. How many days has it been underwater, and did you input bottle bac which cycles for bioload on the first day?

Before adding fish, choose your disease control protocol. See fish disease forums here for examples on skipping disease protocol

I haven't dug for examples, but it honestly wouldn't surprise me given how inaccurate these colorimetric assays are due to 'eyeball-testing'. I'm not blindly trusting the numbers but, given how new I am to the hobby, I also don't want to drop several hundred dollars on electronic colorimetric tests (as much as that would please the scientist in me who's used to that degree of precision).

Why do you say nitrite has no bearing on a cycle?

 

[brandon429]

No degree or frequency of water changes can undo a cycle, bac are stuck. We change initial water so algae fuel is reduced, getting ready to disallow the uglies phase by work, not passive wait.

 

[brandon429]

Regarding nitrite I know it’s a bold claim. Here’s my case:

We should use the collective power of the chem forum to prove or deny the possibility of sustained .25 ammonia in reefing

Why does it matter if reef tanks can have stuck cycles? Because when you move homes you don't want to lose animals, cycling science needs precision and predictability in order to protect our tanks. perhaps an emergency setup is needed, no wait time permitted or If you are invited to show...

www.reef2reef.com

the chem forum and its brains who will hammer a false claim into oblivion are my referees. no detractors there, I’m sure one might pop up in five mins due to this post, but originally you can see there were none. All detractors are not using seneye we are a million percent sure


no param testing is required to cycle. They start macna convention reefs on time using new cycling science, not allowed param testing. If we require proof, it’s via ammonia *dropping* not getting zero.
Their cycles are not weaker, there as good as a five month wait up.

Let’s see a pic of your tank, what kind of bottle bac was used/ how many days ago

 

[brandon429]

What I post isn’t meant to be mean or harm reefing or anything, or just going against rules for anarchy

I’m forcing conflicting concepts to align in my opinion. They said we can’t skip a cycle, but there are two examples below. To reverse engineer them is no harm no foul. What I typed above isn’t against the grain of cycling for the sake of being a jerk, it’s my best interpretation of how these guys and all MACNA gets away with it. Anyone is welcome to riff on these cycles and match them to known rules for setup wait and measure.

instant wet start nano, transferred live rocks get no cycle at all

Two Month Update on the One-Day Nano Reef Tank Build [Video] | Reef Builders | The Reef and Saltwater Aquarium Blog

It’s never been easier to set up a reef tank and this is precisely what we set out to demonstrate in our recent build of starter nano reef tank. In less than 24 hours we took a Red Sea Max Nano from…

reefbuilders.com

instant dry start with highly assertive beyond normal day one bioload. This one breaks nearly all rules but only seemingly, it actually fulfills the updated measure of a closed cycle below though.

Bio-spira works great

I just started a new tank a little over a week ago. I started with all dry rock and new sand. I added a bottle of Bio-Spira and put fish and coral the same day. Never saw any ammonia and fish and coral seem healthy.

www.reef2reef.com

distilled from skip cycle threads, I offer an updated cycle closed definition which makes all concepts align, for now anyways:


a cycle is done when starting bioload is able to be present in an aquarium without enduring free ammonia harm regardless of water changes (proof of encapsulation in biofilm). There are no partial cycles, starting bioload will die or It will live based on ammonia control verified by accurate testers, and it is also possible to start a reef tank using dosed or suspended bottled bacteria as some mixes afford instant ammonia control, the ‘fish in’ cycle. No degree of water changes, volume or frequency can undo a cycle after bacterial adherence to surfaces (allows for assertive cleaning) and a cycle cannot be starved after establishment.


that means you can not undo a cycle by withholding feed once the cycle is complete, it still gets in unless our homes suddenly become ready and staffed sterile microbiology labs (we have three year fallow tests on file) the required bacteria that process nitrite catch up later, well after MACNA has started


reef tank cycling 2020