Co2 And Nitrite

Hi everyone,

I am using a Ferplast CO2 Energy Professional Kit in my 300 litre planted tank.

I started using it and only during the day when my lights were on. I noticed two days after I started using it that my Dwarf Neon Rainbow fish were at the surface seemingly gasping for air. I was pumping approx two bubbles per second into the tank. I did a liquid Nitrate and Nitrite check and to my horror, the Nitrite readings were through the roof. I did an immediate water change (50%) to get the Nitrite levels down. I turned off the CO2 unit and my water returned to normal!

I waited a week and turned the CO2 unit back on this time one bubble per second. That evening the Nitrite levels were again very high and sad to say, I lost one of the Rainbow fish.

The CO2 unit was on for 8 hours per day.

Can an ovedose of CO2 cause Nitrite spikes? If not, what the hell is happening? The high Nitrite readings are always zero until I start to use the CO2 unit. Ammonia is zero and Nitrate is 20ppm. I noted that mu usual PH reading of 7.5 was reduced to 7.0.

My water changing regime and tank cleaning are very good and the tank is well filtered with a UV external filter. I have two airstones in the tank which are in constant use.



Any advice from anyone?

Regards,

Neil

neil1963 said:

Can an ovedose of CO2 cause Nitrite spikes? If not, what the hell is happening? The high Nitrite readings are always zero until I start to use the CO2 unit. Ammonia is zero and Nitrate is 20ppm. I noted that mu usual PH reading of 7.5 was reduced to 7.0.

Click to expand...

In short...No

However something strange is obviously happening within your tank.

Can you give a full spec (size, filtration, lighting, dosing etc) of your tank for us and any pics.

AC

Hi,

Thanks for the quick response.

My tank specs are 128cm (50") Length, 49cm (19") Depth, 54cm (21") Height. Volume approx 300 litres.

2 x 40W Fluorescent Lights 48" inches in length

SunSun external filter with 9w UV lamp - Flow rate: 2000 L/H, Built in 2000L/H pump (Self priming), Water Volume: 20 Litres (Approx)

Fish R Fun Internal 24W UV sterilizer with power head

200w Heater thermostat

Current water Stats
Ammonia 0
Nitrate 20ppm
Nitrite 0
PH 7.5

Could lack of Oxygen cause a high Nitrate reading?

Thanks

nitrates at 20 are no reason for concern and are not high at all. The level that kills livestock is in the hundreds. A lot of planted tank enthusisasts would add 20ppm per week without even thinking about it.

I would guess that the CO2 is what is driving the fish to the top. But I have no idea why the Nitrite seems to be rising as you add CO2!!.

You have about 1WPG by my reckoning and not many plants so I am wondering why you decided to use CO2?

AC

Thanks for the quick response.

There were a lot more in the tank but some died off. Even with liquid plant food supplement and feeding tabs in the substrate.

The plants did not seem to be flourishing and had a bad case of algae. I was given bad advice by a LFS and have now taken advice from a more reputable source. My KH is to high for CO2 so have stopped the use of now!

Thanks for getting back to me.

Unless it is like 40d kh (taking a random guess that is probably way higher than your kh!) then it isnt to high, it has been proven that what is considered to be high in the hobby wont affect CO2 injection.

I dont know what is causing the NO2 spike either, one thing (and the only thing) that stands out is you say that some plants died. When they rot, they give off ammonia which in turn is turned into Nitrite by the bacteria - this is the only thing i can think of