Anerobic Substrate

[Onderdole]

Hi i've have a 80ltr coldwater tank and for 8 months it hads been fine, id been taking care of it well with partal weekly changes and slightly bigger monthly tidy ups.

reciently i was getting patches of the gravel substrate turnign black, some of the gravel seemed to be amost turnign to what looked like little bits of coal it was so black.

then at the weekend the fish looked like they were gasping even after a full water change.

I tested Ammo and Nitrite and the Nitrite was off the scale.

I did a quick check of information and thought it was anerobic substrate causing the nitrate to turn to nitrite

I had vaxed it every week with the water changes but i think that i had too much substrate ( 4inches ) and it wasnt being turned over reguarly enough.

so I transfered fish to temporary tank and totaly stripped down the old tank, everything got a deep clean in rainwater.

I then rebuilt the tank but only put in 1inch of substrate.

I refileld the tank with 80ltrs of tap water with the correct ammount of stress coat.

All was ok for a day but i tested amonia and nitrite thismornign and the nitrite is way way high. Ammo is cleear.

Even thought i thoroughlu washed the old substrate should i have reused it?

could it be the old substrate causing the nitrite spike just one day after a change, has a reaction been started in the substrate that cleaning aint gonna stop

should i clean again and replace with new substrate!

whats other peoples experiences of this

note the pump is big enough for the tank its a internal filter JBL crystal profi i60, its not a pump filter problem im sure of that.

 

[rabbut]

The substrate going anairobic will do no harm in most cases, unless you have it build-up and release a lot of gas in one go. The Anairobic stage of the Nitrogen cycle does break-down Nitrate, but into Nitrogen and Oxygen gasses. The Oxygen gets utilised by the bacteria that "created" it, and the Nitrogen gets realeased into the tank. A by-product, Hydrogen Sulphide, a very smelly gas can build-up in the substrate and release into the water. It oxidises very quickly in water, and hence tends to really reduce the amount of Oxygen in the water, but the by-porducts of the Nitrate removal should not cause Nitrite spikes

Quick few daft questions, if I may?

How often do you clean the filter, and how do you clean it?

How many of what fish do you have?

How big is the tank?

How long has the tank been going?

Have you replaced the filter(s) recently?

What filter type do you use?

All the best
Rabbut

 

[Onderdole]

The substrate going anairobic will do no harm in most cases, unless you have it build-up and release a lot of gas in one go. The Anairobic stage of the Nitrogen cycle does break-down Nitrate, but into Nitrogen and Oxygen gasses. The Oxygen gets utilised by the bacteria that "created" it, and the Nitrogen gets realeased into the tank. A by-product, Hydrogen Sulphide, a very smelly gas can build-up in the substrate and release into the water. It oxidises very quickly in water, and hence tends to really reduce the amount of Oxygen in the water, but the by-porducts of the Nitrate removal should not cause Nitrite spikes

Quick few daft questions, if I may?

How often do you clean the filter, and how do you clean it?

i check the filter each week when i do partal water change, when i do clean it (probably every other week on adverage) i take it appart and shake it and squeese it about in the water ive removed from the tank

How many of what fish do you have?

I've a shoal of about 20 european minnows ranging from 2 to 4cm long
How big is the tank?
80L - 20 gal

How long has the tank been going?

I set tank up end of September 2008, it cycled as per expectations ok, ive not lost any fish in it ever

Have you replaced the filter(s) recently?

Ive not replaced the filter reciently either the filter device nor the media ( sponge) reciently

What filter type do you use?

I use an internal filter wall mounted filter, a JBL CristalProfi i60 (300-800 l/h)

All the best
Rabbut

 

[rabbut]

Very strange, there is nothing there that would be expected to cause you issues with Nitrite running away

 

[Onderdole]

Very strange, there is nothing there that would be expected to cause you issues with Nitrite running away

Rabbut,

many thanks

ive been changign the water and testing and it seems like the bacteria for killing nitrite is killed. That fro eating the ammonia si ok.

Ive another tank and have used some of that tansk media to get the colonies back up to strength, its just a water chaneg game again for a week or two.