Nitrite spike after water change!!

[njparton]

Firstly, let me say that after going through the initial cycling process about 6 months ago, day to day my tank never has ammonia of nitrite readings above zero.

However, I've started to notice that about 2 hours after weekly water changes (I change 20-30%) my fish all exhibit rapid gill movements and look very stressed.

I did a water change this morning and my fish are stressing away as I type. I've just tested the water and got the following results:

dissolved 02 = 8 mg/l
Ammonia = 0 mg/l
nitrite = 0.25-0.5 mg/l
nitrate = 10 mg/l
pH = 7
temp = 27C

My tap water is very good indeed at about pH 7 with no detectable readings of the above chemicals. It is soft to very soft.

I use Tetra Tap Safe as a dechlorinator and only clean the gravel every 3 or 4 weeks so I'm not removing too many bacteria. I did not clean the gravel this morning.

What can I do to minimise this nitrite spike?

I've started to add Cycle additive with water changes in an effort to minimise the spike but there must be another answer?

 

[Cian McLiam]

Do you age the water beforehand? Before I got a de-ioniser I would leave it at least overnight with an airstone in it to release toxins.

Ken

 

[Globel]

I agree with ken you should alwase elt your water age atleast 1 nightbefro putting it in your tank. Unless you got a huge tank that you need to shange 10 gallons at a time i sugest buying watere that the lvfs (1$ a gallon.) Or get a deioniser there like 20$ and you can refill the cartrage. Speaking of that how offten should i change those things. Ken how offten do yuou change yours?

 

[njparton]

But where am I going to keep all that water - it equates to 3 buckets full!!

Surely the job of the dechlorinator is to neutralise all the harmful chemicals and heavy metals within minutes?

Will leaving the water overnight stop the nitrite spike? I'm not so sure....

 

[Cian McLiam]

If you look closely, after a while of standing, bubbles will form on the side of the bucket. Thats all the gases and chemiclas leaving the water, so yes, standing will help! Aerate with an airstone drives the gases out quicker

Ken

 

[njparton]

I understand that argument, but not why I'm getting a nitrite spike...

 

[Cian McLiam]

OK to be a bit clearer, tap water is a processed product, for human consumption. To achieve this, water companies have to add chemicals to ensure the water isnt full of nasty bugs and bacteria, among these are chlorine and chloramines. These are gases dissolved in water and kill bacteria and nasties. They will do the same for your filter, so any chemicals like these left in the water will kill off some beneficial bacteria in your filter, causing the nitrite spike. As they are gases, leaving the water to stand causes them to fall out of solution and dissapate into the atmosphere, meaning the tap water is now less dangerous to the filter bacteria. Adding dechlorinator will make the water less toxic, but aerating removes the gases naturally and also has the added advantage of being at room temperature when you add it to the tank.

Ken

 

[njparton]

Aha

Thanks for that, I appreciate your time.

I'll have to go looking for a water container tommorrow capable of holding 3 buckets full then....

At least I have a spare air pump and air stone.

 

[Cian McLiam]

yay! good plan, hope it works out for you...

Ken

 

[njparton]

Well, today was that time again...

I took your advice and bought a large water container...

About 6 days ago I filled it with water and added dechlorinator. 48 hrs prior to this morning I added a couple of air stones and started aerating it.

And guess what?

Nitrite spike (up to about 0.4 mg/l), all fish at the surface gasping for air. No ammonia detected though.

I'm at a loss.

What's causing this spike? Anybody any other ideas?

 

[snowyangel]

Hey nj, i'm currently going through the same dangerous situation as you. I didn't age my water before hand either and i plan too. I also bought Cycle too and don't know if its making a difference, but hopefully.I was given the advice to get some cultured gravel from someone else tank to get good bacteria. I tried this(but i put a way smaller amount cus im paranoid) and i hope its working. I've found some good websites on Nitrites as I'm desperately trying to find answers also:

http/freshaquarium.about.com/cs/disease/...tritepoison.htm

http/www.fishdoc.co.uk/water/nitrite.htm

This site just explains how often and what the ranges should be for your tests(which you prob already know) : http/saltaquarium.about.com/library/blan...tkitchartfo.htm

And good luck for both of us

 

[sandyd]

I was wondering if when you do water changes do you vaccuum the gravel? If there is alot of debre on the gravel, when you add the new water in, it may be causing your spikes. I do all my water changes through a vaccuum and have never experienced any spikes. In my opinion, it would be worth a try at your next cleaning.
Sandy

 

[njparton]

I was wondering if when you do water changes do you vaccuum the gravel? If there is alot of debre on the gravel, when you add the new water in, it may be causing your spikes. I do all my water changes through a vaccuum and have never experienced any spikes. In my opinion, it would be worth a try at your next cleaning.
Sandy

Not always. I tend to vacuum the gravel every 2 or 3 water changes and it makes no difference - I get a spike whether I've vacuumed or not.

Any other ideas anyone?