super nitrate and nitrite spike please help save my fish

[franchisefish]

i have had my tank up running and cycled for about 3 months i do 20 percent weekly water changes and test my water weekly . today i tested my water and had 0 amonia 5 ppm nitrite and 20 ppm nitrate. this has never happened before. after a 30 percaent water change amonia stayed at 0 nitarte dropped to 2 ppm and nitrate dropped to 10 ppm what should i do now as this is so high any ideas what caused this .? by the way when i do my water changes i use a gravel cleaner to change the water so it sucks up all the crud. please help what to do now?

[wataugachicken]

first, do another (or two) large water changes to remove the nitrate.

otherwise:
what size tank?
what fish do you have and how many of each?
have you added more fish recently?
have you medciated the tank for any diseases? what medication did you use?
have you cleaned the filters or changed the substrate (sand or gravel on the bottom)?
if you use a dechlorinating product, did you possibly forget it last time you did a water change? chlorine, in addition to harming fish, can kill the bacteria that gets rid of ammonia and nitrite.

[franchisefish]

29 gallon tank with 13 small assorted glo danios no new fish or decoration ALWAYS use dechlorinator ..api stress coat for dechlorinator no other chemical ever medium size gravel

[franchisefish]

please help!

[wataugachicken]

do you have any live plants in the tank?

[leighasnana]

Are you using the test strips to test your water? I've never used them but they are known to give innacurate readings.

Are the fish showing signs of distress?

[doreenjoy]

All you can do is partial water changes to get the nitrIte to reasonable levels, like 0.25 ppm.

[Cory Keeper]

yes, what kind of test kit are you using?

[OldMan47]

If you have done a gravel vac of the whole tank, you may have mixed the top layer that was in good contact with the water down into the substrate and moved some less populated gravel to the top. This won't destroy your gravel component of the biofilter but will reduce its effectiveness for a few days. Only do part of the gravel each time to avoid this problem. Meanwhile I would do water changes without gravel vac until you get the nitrites under control.

[Weezer]

first, do another (or two) large water changes to remove the nitrate.
.
You will always see some NITRATE, Mine is usually between 5-10, the NITRITE should be 0 along with the Ammonia, As suggested do a few more PWC's to get the Rites down.....:)

[ct-death]

You said your tank is 3 months? Did you recently do a filter media maintenance? Either replacement or washed it out? If so, did you use old tank water to rinse with or tap? When you refil the tank, is there a lot of "stuff" kicked up (floaties)?

Regardless, you need to perform WCs necessary to maintain safe levels of ammonia/nitrIte concentrations. For example, if you nitrItes are at 2ppm, you will need to do 2-3 50-60% WCs to get this down... Do one (1) WC and wait 3-4 hours before doing the next.

Personally, the weekly 20% PWCs you are doing (i assume you gravel vac each time?) is a minimum. A few things that could casue this:

- If you don't gravel vac each time this would certainly build up the refuge in the substrate and the water changes probably kick up a lot of "stuff", which in turn will rapidly plug your media up! (Keep up on those vacs - I do ~40-50% vac each week)

- Your media will need to be serviced every 4 weeks. If this has not been done, I would suspect this.

- When you feed, does the food settle to the gravel? If so, do you vac this out before the end of the day? Excess food can cause these spikes as well, if in excess

Personally, I get this settled with WCs (Bravo BTW on testing weekly! ;)) But I would just increase your weekly routine WCs to around 40% with gravel vacs each time. I suspect this, overtime was the casue.