Nitrates remain after several large water changes

[Realamerican13]

Hey guys, cycling a 25 gallon IM lagoon. Started with live sand, caribsea rock, some bio balls from friends tank and some water from his tank as well as fresh saltwater. Started by adding bio spira and dosing ammonia at 2 ppm until it dropped it zero. I have done this 3 times. When the tank was going from 2 ppm to zero in ammonia with zero nitrites i did a 5 gallon water change. Nitrates were still sky high. Did another 5 gal water change, still high. Let it sit for a few days, just did a 10 gal water change, nitrates are still reading 20 ppm (it has gone down, readings were off the chart in previous tests) but I feel this is still too high. Also I havent dosed any ammonia since starting the water changes, yet today I am reading .5 ppm ammonia on the tests as well. Wondering if Im doing anything wrong (first tank), and how I can get these nitrates down. Any ideas why my ammonia went up when I didnt add any ammonia. Tank is fishless right now. Friend has 2 clowns in quarantine ready to go in when tanks ready. Only thing I can think off is the rock he gave me was previously live, stored in fresh water. Rock had no algae on it or any dead matter that I could see. Thanks in advance for the advice. Excited to get these clowns in but dont want to put them in until tank is ready.

 

[Realamerican13]

Using api test kit, also seachem ammonia badge is showing no ammonia in tank

 

[brandon429]

It will be easy to get your cycle on track, using zero test kits

How many days total has your system had saltwater in it

Is the rock specifically liferock with painted coralline bacteria mix

Additional bac sources stated just for notes: used water, used bioballs.


Testing error and confounds like water conditioner use make test kits unreliable for cycle determination, but we have another way from the books regarding established timelines + the fact you used ready surfaces for inoculation. If you will post a tank shot and # of days underwater, can make sense of the cycle by using known deposition times, not the stated test params.


Caribsea life rock is an active filter I bet within a week of hydration needing nothing else, their website states the times if applicable

You have provided raw ammonia, factored time booster.

Whatever the testers happen to read interim couldn’t matter less...some will be right, some will be wrong.


I have one particular thread where a gent ran two testers on one sample and got a fifty ppm nitrate spread, at that point I realized we’ve all been horseshoeing for thirty years and believing any reading without pause. using biology and submersion time is the most up to date cycling technique it beats the pants off using test kits to determine a start date.

*if at any time someone wants proof of cycle completion using ammonia oxidation proof testing we can provide that using any tester
am only saying that we know the cycle completion date with or without testing. We need here to know how long the tank has been underwater

 

[lapin]

Using api test kit, also seachem ammonia badge is showing no ammonia in tank

API not the best test kit.
To get your nitrates down, change out 80% of the water. If that does not work then you have a reason to suspect other causes like: if you used some free once live rock from a friend. Takes on average 4 to 8 weeks to cycle a tank.

 

[stevewright1]

when you say Nitrates are high what exactly is the number?

bear in mind that a 5 gallon water change in 25 gallon system is approx 20% (could be more depending if the 25 galls is water volume or some of that occupied volume is rocks and sand etc ) and as such you should expect about 20% reduction in nitrates
thus if your test indicated 50ppm before water change then they will still be 40ppm even after that water change (in fact close enough to be between colors on most charts and may well look like nothing had in fact changed)

 

[Realamerican13]

Tank has been cycling for 3 weeks, I have stopped adding ammonia because i dont want the nitrates to continue to get higher. When i was adding ammonia, the tank was processing 2 ppm in about 36 hours. First water change was 10 gallons, got nitrates down to about 50 ppm. Second water change was done 4 days later, nitrates are now at 20 ppm. Planning on doing another 10 gallon water change.

 

[Realamerican13]

 

[brandon429]

Your cycle is done because that’s long enough for bacteria to colonize all surfaces, that appears to possibly be pre cured live rock anyway that had all bac the day it showed up, and you’ve already been measuring ammonia performance which is the only factor that matters in reef cycling.


Anytime ammonia is being reduced in an aquarium using time + water + bacteria, nitrate is being produced but we may or may not measure that accurately with our color testers, and nitrite is fully neutral in reefing it has no bearing on any cycle and is the most unneeded to know test param in all of reefing.

In your case, nitrate is working fine and having some is expected. It’s an algae param at this point.


Are those white dotted fanworms attached to that rock?!

How you test the current wastewater varies, and doesn’t matter the reading. The reason your tank is cycled is because if you do a full water change, making it not wastewater, then your tank can handle bioload without crashing in 12 hours as an uncycled system would.

If you wanted final proof that no skeptic could deny, do a 1 ppm ammonia test on the full water change system. It’ll pass. Then you’ll have more nitrate again not coming from cool fish swimming around, but we can add it to our collection of five hundred tank cycles collected

 

[brandon429]

If that is true live rock cured somewhere else before your tank, then it is a collection of respiring organisms always producing trace ammonia and nitrate ad infinitum. The rock may or may not be degassing the nitrate in denitrification, who knows.

That combined with partial water changes earlier and the ammonia dosing explains why nitrates persist

 

[Realamerican13]

The rock that is in the tank was previously used in a tank but has been stored in freshwater for about 6 months before it went in my tank. Not sure if those are white dotted fan worms, Im not familiar with them, I cant see anything moving on the rock if that helps. So I have 2 questions. Should I leave that rock in the tank or is it going to cause me problems? I could go buy new live rock and start over. I have 2 clowns in a friends QT, after an additional water change assuming the nitrates drop, is it safe to add them?

 

[Lasse]

What´s your nitrite (NO2) ?

Sincerely Lasse

 

[brandon429]

It’s ready, that rock is just fine because in three weeks + bottle bac that would bring up all dry surfaces, that yours were stored in freshwater doesn’t matter. Your reef is ready.

Nitrates nor nitrites affect your decision on fish, and at three weeks we already know what your nitrites are due to online cycling charts. Today’s tests for nitrite are almost never correct, and, we’ve covered that any future testing should be done post full water change, not the wastewater of partial water changes. read this thread to see why nitrite and nitrate testing do not factor in your cycle being completed...we can’t even test accurately for them in the majority of cases, not the minority. The freshwater storage would kill former live rock organism inside, and they have to rot away to zero before that rock doesn’t produce some nitrate but it’s harmless, use the rock. It’s in great condition and has a full complement of updated nitrifers because you cannot hydrate inoculated surfaces for three weeks and fail to get a biofilter

https://www.reef2reef.com/threads/the-microbiology-of-reef-tank-cycling.214618/

 

[Realamerican13]

Nitrites are zero Lasse

 

[Lasse]

Can you confirm that with another test ? (another brand) because for me it seems that all that you have writen indicate a nitrite problem - resulting in fault nitrate readings. Is the test you use with two chemicals ? If so - do the test as it should be done but do not add the first chemical - only the second, If you get colouration - you have a nitrite problem. At least it is that way with the tests I normally use. Do not know about API - but if it is two chemicals - it should be the same.

Sincerely Lasse

 

[Realamerican13]

API tests nitrite with only 1 chemical, for nitrate it used 2. Just did a 8ish gallon water change, results were 0 ammonia, 0 nitrites, and around 15-20 ppm nitrates after the water change. I put in another bottle of bio spira just to be safe, acclimated the 2 clowns and added them to the tank. I have filter both on both sides, and 2 bags of chemi pure blue in a media basket. Fish are moving around the tank, no labored breathing, and ate some pellets i dropped in.

 

[Lasse]

I´m sorry if I was unclear. I meant the nitrate test. They works in this way. Chemical 1 is a compound that transfer some of the nitrates into nitrite. Chemical 2 is a nitrite reagent.. The colour chart is adapted to show you your real nitrate level based on time and how much of your nitrate has been changed to nitrite, This means that if you have nitrite in the orginal sample (before adding chemical 1) - you will have a false answer. But it also means that if you only use chemical 2 - you can get a hint that you have nitrite in your original sample - not how much but it will give you a hint. If your nitrite test show 0 and if you do the test the way I describe with the nitrate test - only use chemical 2 - and get no colour change at all - you have confirmed your reading of nitrate and your cycle is done.

Sincerely Lasse

 

[Realamerican13]

Lasse, I did the nitrate test with only the 2nd chemical, came back with no color change. So cycle is complete, not sure why I still have nitrates after doing basically a 100% water change inside of a week.