The NO2 and PH levels keep dropping in my fishtank?

Question

My friend is keeping her fishtank at my house while she moves. She had come over and set it up and everything seemed fine, but 2 days later 2 of the fish had died and the NO2 level was as worse as it could get. She changed the water and added more filters and air pumps. Then the next day the NO2 was horrible again as well as the PH. Are there any specific problems we should be looking for?

Answer 1

The nitrites are jumping up due to a disturbance in the biological filter. Be sure you are keeping a close eye on the ammonia as well. The best solution is continued water changes until the bacteria catch back up with the problem.

As far as the pH, that may be due to a difference in your pH and the pH of the water she was previously using. Check the pH and the tap and then check the tank before and after a water change and look for a pattern.

Feel free to email me if you need additional help with pH and hardness issues.

MM

Answer 2

There is some kind of hiccup in nitrogen cycle. Nitrite levels in an established tank should be zero. If you're seeing NO2 then something has upset the cycle. This can occur from adding new fish to the tank, adding all new filter media, heavily cleaning the substrate and sometimes from emptying the tank completely and refilling it with new water. (Like in a major move). Usually in a well established tank one of these things wouldn't be enough to upset the cycle but a combination of things might. Also a large pH crash can kill off the bacterial colonies. Once the tank begins to recycle itself again the bacteria would regenerate and the nitrites would spike. If you are having pH crashes you should check your buffering capacity. (KH) This is also called carbonate hardness and the test kits can be purchased inexpensively at any local fish store. KH is what holds the pH stable. When it's very low the pH can bounce all around and usually falls rapidly. (Know as a pH crash.)

I experienced similar problems when I lived in the Boston area where my water had almost nonexistent KH levels. To overcome the issue I added buffers to the water at every water change.

Answer 3

If she washed out the filter and gravel, or there was an extended delay in moving it and setting it up, she's probably killed off the bacteria colony that controls the ammonia/nitrites. The PH is probably off from using the water at a different location and was put in unconditioned I'd imagine. I am a bit hesitant to reccomend stresszyme or ammolock here, it would probably give you a temporary solution, but then these fish are going to up and move again right? They would end up going right back into these same conditions if the filter and gravel gets washed out again. Now if this is going to only be a few days I doubt thats going to matter, but if that tank ends up being thier weeks, I'd not wash out anything and try to retain as much of the water as possible to keep that bacteria colony alive.

Answer 4

Your tank is most likely poorly cycled while at the same time too high in bio load.
Organic mulm will produce acids as it decays leading to pH crashes. I would strongly recommend adding a seasoned filter media or filter itself, a product such as Prime to neutralize your nitrites (and probably ammonia). I would also check your KH level of both your tap water and tank water. If is it is less than 50 ppm you need to add a buffer such as seachem or a mineral block such as Wonder Shell (which will also add electrolytes that will ease the stress caused from the high nitrites)

When you change water, make sure and use a gravel vacuum, never take gravel out and wash it as this will disrupt your aquarium nitrogen cycle (not that you did this).

I recommend reading this article about the aquarium nitrogen cycle;
http://www.americanaquariumproducts.com/Nitrogen_Cycle.html

As well as this information site with links to current articles about cleaning and FW basics and more;
http://www.americanaquariumproducts.com/Aquarium_Information.html

Good luck with this!

Answer 5

water is not right.
check the water quality.
do water change everyday 10%.
use stress enzyme solution and stress coat solution.