View Full Version : High Nitrates mid cycle

09/24/2017, 12:22 PM
Hi All,

This is my first post, I have kept a tropical tank for around 3 years and finally taken the plunge into a salty tank.

I have been running my tank through a fishless cycle for less than a week (done LOADS of reading into it) but I am not sure what it happening. Please see a log of my test reading using an API liquid master kit since getting the tank.

Day 1
Tank running - no tests done

Day 2
Ammonia 8

Day 3
Ammonia 8 (possibly a little less)
Nitrite 2

Day 4
Ammonia 4
Nitrite 2

Days 5
Ammonia 3
Nitrite 3
Nitrate 80

Day 6
Ammonia 0.25
Nitrite 5
Nitrate 140+

I am really pleased with my results of ammonia dropping and nitrites increasing. I have been adding Fluval cycle bacteria enhancer (as per instructions) and also added some aqua evolution pure reef balls on Day 2.

I am however a little concerned about the high Nitrate levels as it is really hard to tell the colours apart on the test kit so I suspect it could be higher. Are these Nitrate levels too high during a fishless cycle and warrant a water change or should I allow them to continue to rise and just expect to do a very large water change at the end of the cycle?

Thanks in advance!

09/24/2017, 12:30 PM
Did you add ammonia to start?
Thats insanely high ammonia levels to start and absolutely the reason you have sky high nitrate levels all though you don't get accurate nitrate readings when nitrite is present too..

I would stop the Fluval dosing if you haven't aready and do a very large water change to get those nitrate levels down. Then just wait until the cycle finishes..

Did you start with dry rock or shipped live rock or locally sourced live rock?

09/24/2017, 12:52 PM
Hi mcgyvr. I presume that the ammonia spike came from the fluval and\or live rock die off as I added no other ammonia.

I stopped dosing the fluval stuff after day 4 as the instructions only say to dose for 3 days, the instructions also say that you can add fish straight after these 3 days but I was never going to do that!

Started with a mixture of rock, the tank is second hand so I kept the sand\rocks that were originally in the tank (kept wet during transport) and then added some rock that had been in a dark unheated bucket of salt water for a few months.

I only have a small amount of salt left to mix up the water so I will do the biggest change I can with what I have for now and look to get another change done tomorrow.

09/24/2017, 12:56 PM
Let it cycle and check your water parms after 3rd week. There is no reason to do a water test in week 1.

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09/24/2017, 01:16 PM
There is no reason to do a water test in week 1.

If you are using dry rock and not using any "Cycling/bacteria" products then yes as the process when done that way will take longer than 1 week..

When "fast cycling" or using live rock,etc.. then you can certainly cycle a tank in a week or less..

They used "some" live rock here so the high ammonia is likely from the Fluval product itself and quite frankly is probably causing more problems than it solved...

09/24/2017, 01:18 PM
Thanks both for your advice, although it does leave me unsure of what to do.

I have done a small change of 5L in a 120L tank as that's all that I have salt for at the mo, wasn't expecting to be changing water so early.

I will keep an eye on the levels. mcgyvr: when you sat that nitrate tests aren't accurate when nitrate is present, does this mean that I may be getting false results and so it isn't as bad as it reads?

Should I not be trying to keep the ammonia to a certain level during the cycle to keep bacteria types growing\alive?

09/24/2017, 01:24 PM
I guarantee you have high nitrates... but yes nitrite can confuse the nitrate tests..

I'm telling you to change the water because nitrate levels that high are bad for everything and will just cause you more problems down the road..
Some people think its bad to change water during cycling.. Thats just BS...
You are just going to have a serious nitrate issue and have to work your *** off later if you don't tackle some of it now..

And yes.. ammonia levels over 2ppm are always bad during cycling and higher levels have been shown to be detrimental to proper bacterial growth,etc... never dose or let them get higher during cycling.. usually 1ppm is plenty..

But now you have NO NEED at all to add anymore ammonia..
There is no need to add more to feed existing bacteria.. DO NOT ADD ANYTHING ELSE..

You can wait and not do anything but top off with fresh water to replace whats evaporating but IMO one large water change to clean up some of that water is better than not waiting and doing nothing..

09/24/2017, 01:43 PM
All makes sense mcgyvr

I'll get some salt tomorrow and keep doing small regular changes as the cycle continues. I am worried that by changing water I will also be removing the nitrites and thus the bacteria wont grow to the needed levels.

I also wont add anything more to the tank, cant wait to add some fish to the tank but really want to be sure the water and bacteria are right first.

09/24/2017, 01:55 PM
I am worried that by changing water I will also be removing the nitrites and thus the bacteria wont grow to the needed levels.

That absolutely is not an issue and will not happen at all..
Tanks can sit for months (up to a year or more as shown in some studies) without any additional food source to keep the bacteria alive..

And as far as water quality/food goes.. yours is a cesspool of disgust at this time :lmao:
Its an absolute bacterial rave going on in there now..party woot woot.. ;)