I'm stumped! Nitrates??`

[YamNato]

Hey there, so I'm stumped as to why I have no nitrates in my tank. 

I had been given a small tank with 2 fish in it from a friend. Had no clue about water perimeters etc. I didn't like the fact that the tank was so small. So bought a 48l (still small but better). Set it all up and then transferred fish, the fish died. I did research and found out about the nitrogen cycle etc. Set tank up again, let it run for 3-4 weeks, went to a popular pet store chain (don't want to mention names), had the water tested, and all clear except she said my p.H was very acidic and to do a water change but I could buy fish. So I told her tank size etc and I bought a bristle nose pleco and a red tail shark. Get home, do a water change, put them in the tank. The next day I notice the shark doesn't look happy, so I decide to take my water to another store and get it tested. Turns out I had slight amounts ammonia and nitrite but the kicker was my p'h was 8.5 (turn's out my bore spews out 8.5-9 p.H and 8 dKH). So I rush home do all I can to get p.H down over the next week and get the ammonia and nitrite levels down. After 3 weeks, ammonia is 0 but still have some nitrite. I was told to use some Nitrozorb, sorry if that's not the correct spelling, so I bought some and put it in.

3 days after that I went back to my now LFS and get water tested again. Again slight amount of nitrite but less this time, told to do a 40-50% water change and use the nitrozorb again (after recharging). I also decided to buy a master test kit. 2 days later ammonia = 0, nitrites = 0, nitrates = 0. Mind you this hole time I've been dosing Stability.

Awesome water = great, both fish have survived and now I'll wait several days before I get more fish. So the 18/2 I did the last water change and from that day I've had 0,0,0 until yesterday. Two days ago I went to the LFS had water tested, I took my note book along and showed my records since the 18th showing 0,0,0. He said the water was perfect but 0 nitrates is a good and bad thing because well where are they. I bought 5 cherry barb's

Last night, when I tested my water my nitrites had risen, only slightly, I had to test against tap water to be sure but it was a darker blue. This morning, I tested again and I would say it looks like 0.10ppm of nitrites but still 0 ammonia and 0 nitrates. I dosed some prime to keep fish safe and stability to help bacterial colonies. Will keep testing. I have had 4 plants in the tank and after Friday I now have have 6 + some Java moss in there. I also have 2 huge pieces of drift wood. I do have lots of algae to control. Can these alone keep my nitrates at 0? Keeping in mind, the last water change I did was on the 18th? Now with the nitrite spike I wonder if the cycle isn't complete. 

On another note, something is buffering the p.h of the water up. my current dKH is 2 (when I test it at home but for some reason is 0 when tested at the LFS). I'll p.H test in the morning and its around 7.6, I will add some p.H down. At night when I get home it's a good 7.0. Next morning I'll test and its back up at 7.6, I'll repeat with p.h down. This happens most days.

I've mentioned in another post about a new African tank I'm setting up but I feel like I'm losing a battle with this smaller tank, and I will not let it fail.

I'm not sure if I'm over thinking things or what.

Any input is appreciated,

Thanks

[Adrienne]

If you continue to do regular largish water changes ie 40-50% your cycle will still be going and that will be why you have zero nitrates.  You are correct 'now with the nitrite spike I wonder if the cycle is not complete'.  Nitrate tests are a precise thing, if you do not follow the instructions exactly (and I am not suggesting you are not, but the lfs may not be) then you will not get an accurate reading.   Bristlenose are the biggest waste producers ever and your tank is a bit small for even one - they will keep your cycling going.  Unfortunately nitrite, as you know is toxic to fish, prime will help lock it into a non toxic form but you will still get readings.   Your driftwood will help lower your pH.  Fish can adapt to higher pH readings, but are less likely to breed.  Swinging pH is far more damaging than pH that is stable but not where your fish prefer it.

My recommendations:

Try changing 10% daily or every couple of days, continue with prime and nitrozorb (it does work) and do as you are doing, keep an eye on your tank readings. 

Don't add any more fish or plants until it is sorted.

It takes several weeks for a tank to complete a cycle (depending on how you do it).

Edited February 28, 2016 by Adrienne

[YamNato]

If you continue to do regular largish water changes ie 40-50% your cycle will still be going and that will be why you have zero nitrates.  You are correct 'now with the nitrite spike I wonder if the cycle is not complete'.  Nitrate tests are a precise thing, if you do not follow the instructions exactly (and I am not suggesting you are not, but the lfs may not be) then you will not get an accurate reading.   Bristlenose are the biggest waste producers ever and your tank is a bit small for even one - they will keep your cycling going.  Unfortunately nitrite, as you know is toxic to fish, prime will help lock it into a non toxic form but you will still get readings.   Your driftwood will help lower your pH.  Fish can adapt to higher pH readings, but are less likely to breed.  Swinging pH is far more damaging than pH that is stable but not where your fish prefer it.

My recommendations:

Try changing 10% daily or every couple of days, continue with prime and nitrozorb (it does work) and do as you are doing, keep an eye on your tank readings. 

Don't add any more fish or plants until it is sorted.

It takes several weeks for a tank to complete a cycle (depending on how you do it).

Thanks for the input

Yeah that's why I was stumped that for 10 days, with no water changes and with two messy fish (RTS and pleco), I had 0,0,0. Then nitrites.

I test morning and night so I am keeping a close eye on it. Will keep the post updated, will be interesting to see what happens with the 5 extra cherry barbs.

P.S the pleco and the RTS will have new homes when they get bigger. The Mrs has said I am only allowed 2 tanks so I will get the 210l African tank going and then the 48 will be upgraded to a 100l and be a heavily planted tank. THAT IS THE PLAN anyway haha.

Cheers

Edited February 28, 2016 by YamNato

[Ira]

You have a moderate sized tank, small bioload, lots of water changes and you keep absorbing the nitrates, etc using nitrazorb?  I'm not surprised. Just keep doing water changes for a week or two, stop complicating the process by adding chemicals and nitrazorb.  It should be cycled in another week or so.

[alienara2]

This was my experience a few months ago... until I was told that I had to shake the test bottles until my arms were sore. Something about crystals having to break up before it could test properly.

Now, if you're having 0 nitrates, it could be 

1. The cycle isn't complete and you're still going from ammonia to nitrite, but the bacteria colony for nitrite to nitrate isn't sufficient yet.
2. The test may not be accurate (not shaken enough or potentially expired tests?)
3. If doing huge water changes and water is not dechlorinated, it may be causing the bacteria in the filter and tank to die, hence restarting or delaying the cycle.

Personally I use water straight from the tap when doing water changes but I only do 15%-20% at the very most so it's usually diluted enough that the bacteria aren't too adversely affected.