High Nitrite Levels

[joe 81]

so i had my tank up and running for about 3 weeks with 7 silvertip tetras, 2 julii corys, 2 common plecs and 2 dwarf gouramis. A week later i addes another 8 silvertips, 3 green tigerbarbs and a red tail black shark. later that day i measured my nitrite levels and instead of being <3mg/l it was 1.6mg/l i started to panick and did a 30% water change to not much effect. 2 weeks an about 8 water changes on they are slightly lower but not a lot. i am almost certain that i added to many fish at once. i am still doing regular water changes but is there anything else i can do to lower my nitrite levels? thanks for any help.

 

[arobinson1984]

With high ammonia or nitrite levels above 1mg/l you will need to do much larger water changes, more like 80-90%

A 30% change wont do anything, by the time you come to do another the levels will have risen again rendering the 30% useless.

What size is the tank? Dimensions?

Have a read of the fish-in cycle thread that is linked in my signature.

Andy

 

[joe 81]

With high ammonia or nitrite levels above 1mg/l you will need to do much larger water changes, more like 80-90%

A 30% change wont do anything, by the time you come to do another the levels will have risen again rendering the 30% useless.

What size is the tank? Dimensions?

Have a read of the fish-in cycle thread that is linked in my signature.

Andy

Measurements: 101 x 41 x 50 cm
it's 180 l (40 gal)
thanks for the help

 

[waterdrop]

Hi Joe and welcome to the beginners section!

You're absolutely right! You added way too many fish, way too soon! A new freshwater aquarium usually shouldn't have fish in it for the first couple of.. months! That's because, instead, it should be undergoing what's called a "fishless cycle" so that it can have a correctly working "biofilter," a prerequisite to having fish.

I agree with Andy, you're now in what we call a "Fish-In Cycling" situation.. not a pretty thing, but one that we see a lot and so have a document for and a lot of members that can help. Take a look at the document that Andy's pointed to and perhaps there are others in our Beginners Resource Center.

Those water changes need to be as large as possible, as he says, with good gravel cleaning going on as the gravel siphon takes the water out. Take the water as far down as you can without the fish flopping around on the gravel. You can leave the filter and heater running if they are still submerged enough, but be careful about that as it won't hurt to turn them off in in doubt.

Use conditioner (to remove the chlorine/chloramine from the tap water) and rough temperature (your hand is good enough) matching for the return water. You may need a couple of these in close succession to reset your toxin levels down close to zero. If you want to test between water changes then give the water about 20min to mix.

In Fish-In cycling, you'll need to learn to be a bit of a detective. You want to figure out the percentage and frequency of water change that will keep both the ammonia and nitrite, as measured by a good liquid-reagent based test kit, below 0.25ppm until you can be home again to test and change water again if needed. So you'll want your water change to take you down very close to zero ppm for both ammonia and nitrite(NO2) and then only be able to rise to 0.25ppm at most by the time you check at about 12 hours later. Most people pick a morning and evening time about 12 hours apart for their tests and water changes such that each of these hours is a time they'll be home.

On average it takes about a month for the two desired species of beneficial bacteria to grow in the filter while you are personally being the manual filter for your fish by changing out lots of water. Eventually you'll find that you can go two days in a row without getting any traces of ammonia or nitrite and without doing water changes and that will tell you that you're almost cycled, with just perhaps a week of confirmation needed to verify that no more traces happen, after which you can ease down on your testing.

Good luck and hang in there. The members here are great and they'll help you out all along the way.

~~waterdrop~~

 

[joe 81]

Thanks how often should i do 70-80% changes? i have been doing 30% every other day since they rose.

 

[waterdrop]

Well, percentage of water changed is not really the primary number of importance. The thing of most importance is the the number you get from your liquid ammonia test and your liquid nitrite(NO2) test.

Ammonia, in even tiny amounts, causes permanent gill damage leading to shortened lives or death. Nitrite, in even tiny amounts, causes permanent nerve damage leading to similar results. The amounts of tolerance and degrees of damage vary by species but the number we generally work with is 0.25 ppm of either of these bad substances.

Sometimes beginners get confused that changing large amounts of water might be dangerous to the fish, but don't realize that exposure to ammonia or nitrite(NO2) is far worse. So the water changing is in service to the thing of getting the toxin levels down below 0.25ppm and keeping them down below there.

Sometimes, in a heavily overstocked tank in a fish-in situation, it will not seem at first as if you can get the levels down that low, but repeated maximum water changes with gravel-cleaning should in fact get you down there, usually after two back-to-back large changes. You just have to use your test kit to find out what you accomplished. Note that you let the water mix about 20 min or so after the last water change to get a more realistic test.

In rare cases not even massive water changes would handle the waste output of overstocking and fish would need to be re-homed to get down to a reasonble level to be able to accomplish the fish-in cycle.

~~waterdrop~~

 

[joe 81]

ok thanks, so once its back down shall i go back to weekly 30%?

 

[Harlequins]

Depends what your daily water tests results read for ammonia/nitrite,if anything above 0.25 you will need to do a water change to bring it back down,you may end up doing them daily or twice a day depending on the results.

 

[OldMan47]

You do not go back to weekly, you go back to testing and letting the tests guide your water changes.