View Full Version : please help.

07-14-2003, 05:24 PM
what causes nitrate and nitrite levels to be high?

When I test the quality of my water all other paramiters are fine but my nitrite is of the scale and my nitrate is in the unsafe zone.

in the last week I have lost 4 convics and I want to keep my pacu and oscars healthy. I have tried water changes but it doesn't seem to change I did a 25% last night. it is also hard for me too do water changes as with a 55 gallon I have a hard time letting water sit. and almost have to take it from a hose and then add stress coat.

any suggestions?

07-14-2003, 06:09 PM
Overstocking will cause those problems. An oscar by itself will fill a 55g. The nitrite turns into nitrate during the tank's cycle. Then the nitrate gets removed by waterchanges. Massive water changes will help now.

I have about 18-20 tanks from 5g to a couple of 125g's and I just change the water with a python, then add the stress coat (I use Prime) straight to the water. I do that with most of my tanks. Waterchanges will slow down the cycle, but it's better than having the fish die off. Make sure the water is close in temperature (not too cold, not too hot).

07-14-2003, 07:03 PM

My immediate concern would be the Nitrite. How long has your tank been set up? It may not have cycled yet.

As jonah said, just add tap straight to your tank, and add the dechlorinator as you go. I use Prime which will also help to detoxify Nitrite and Nitrate(or so it says), or Genesis. Mostly they are all the same. I stay away from stress coat and anything with aloe in it-it only adds to the nutrient level in your tank, and that is the last thing you want to do right now.

If your tank has been up and running for a while your gravel may need siphoning or you may have a dead fish laying under a rock or something.

You must find out the root of your nitrite problem, and soon. By the species you are keeping in your tanks it is probably overstocking as those fish can become very large. I have seen 30lb Pacu's. They are really not meant for a normal hobbists tanks.



07-15-2003, 09:22 AM
You might also want to test your tap water. You may be getting some nitrogen directly from your local city water trearment plant. As for the pacu, ours are about 25lbs and taller than a 55, so you are going to have some tank size issues.

07-15-2003, 09:28 AM
Yes you might test your tap water for Nitrate-but as for nitrite which is your main concern right now, general water supplies do not have detrimental nitrite levels in them. The EPA standards are quite high as to acceptable nitrite in the public water supply.


07-15-2003, 09:04 PM
Over feeding, dirty filter media, inadequate filtration, overstocking, poor maintenance, dirty gravel, uncycled filters are all causes of high nitrite levels. The only way to get the levels down is water changes.

Let us know what the other parameters of the water conditions are. Have you tested for ammonia too. Both ammonia and nitrite will kill your fish quickly. Depending on the pH of the tank, it is really important to understand that the higher the pH, the more toxic the ammonia, nitrite and nitrate.

07-16-2003, 12:49 PM
Yes, listen to Merlyn she hit the nail on the head, however there is no correlation between PH and Nitrate toxicicty.

Regards all,


07-16-2003, 10:29 PM
Well spoken about the nitrates, Matt!

And just to add to what Matt has said...
It has been noticed in scientific studies that there is a higher incidence of illness and disease among captive fish that are constantly maintained at higher nitrate levels. It wears down their natural immunities and they become stressed and less able to fight off the normal bacterial/parasitic activity in the average aquarium.

Remember, in the wild these fish live in waters of usually less than 5ppm of nitrate. In captivity they become accustomed to somewhere between that and probably between 20-30ppm. My personal observations and experiences on this issue are that if the nitrates go above 20ppm the fish are stressed and more likely to succumb to some kind of illness or problem.

I usually have a nitrate reading of about 10-20ppm nitrate in my tanks on the average. It creeps up to around 30ppm when I need to change water. And keep in mind, my tanks are hugely overstocked!
:nervous: This is a constant source of mental stress for me, since I like to keep it down to like 10ppm, but you can't have huge amounts of fish and not have a nitrate issue. (Unless you change water every day!):D

07-17-2003, 07:57 PM
Pretty simple explanation..... the tank hasn't cycled, or the stocking level has increased so much recently that the tank is facing a much bigger bio-load all of a sudden and must "re-cycle".

07-17-2003, 10:52 PM
I think maybe the tank hasn't cycled. I usually do a 20 percent change every week I just bought a professional testing kit as opposed to the test strips I was using. what bothers me is I also have a grey cloudy water issue and people have been telling me the best way to clear up that is not to do a water change. I syphon the gravel every time I do a water cheange too.

07-18-2003, 07:09 PM
Grey water is normally a bacterial bloom which is caused by disturbing the colony of bacteria in a tank. I'll bet you are over vacuuming the gravel (i.e. removing too much of the bacterial colony), and your tank never really has a chance to get "established" once and for all. It isn't a good idea to syphon the gravel all the time........... at most siphon about one third of the substrate at one time.

I can clear the issue up for you, but first tell me what remains in the tank.....

07-18-2003, 09:46 PM
I was told that it's okay to vacuum all your substrate if you just skim the surface to remove loose surface material. Then you shouldn't deep vacuum more than 1/3. is that correct?
Thanks, Sam

07-21-2003, 05:20 PM
Merlyn, wish I could help your over stocking problem when I come visit my Dad at good old Leisure Village West-have no way to transport fish though.

Why don't you thin out the heard a bit, take a bit of the stress off?:)



07-22-2003, 09:14 AM
I tested my waters last night. I bout another above ground filter last night so in my 55gallon I have two penguin 60's. these are the largest you can get from walmart and I should have plenty of filtration. my nitrate levels still show to be high. some of the cloudyness is still showing. I put some of my gravel from an established tanks in the resovwire(apelling) for my above ground filters hope this will clear it up some and promote good bacterial growth. I have a 5gallon bucket of water that has been sitting out a week with an air stone I used prime on and have been keeping some shinners I use for food in. I may do a quick surfice vac to get the larger stuff(mainly turds as I hand feed my fish so I don't think over feeding is an issue).

a small 5 gallon change won't hurt anything will it.

07-22-2003, 09:18 AM
I know I probabley don't want to be adding fish at this point but I have some tinfoils in another tank that are getting tore to hell by some other pacu I have, when the water clears up can i add these? or a texas chiclid about 4 inches long? The texas is just so mean I don't want him messing with my other fish even though there 5 or 6 times his size. he almost killed an oscar twice his size before.

07-22-2003, 07:10 PM
Geez, Matt, I don't know...if you drove you could get a small power inverter and run a seasoned sponge filter off an air pump. I have plenty of buckets! :lol:

Hey, my parents are right across the street in Leisure Knoll! :)

07-23-2003, 04:03 PM
I decided to try and put some gravel from one of my established tanks in my above ground filters. this is actually working the water is better today then it has been yet. I also didn't change the water this week either.

I'll post it else were as this is probable not the best forum but can I put my jack depsey 4 inches or my texas chiclid in with my other fish? also I got some tinfoil barbs that are getting the crap kicked out of them in my 30gallon if anyones close to tallahassee and wants them. there about 6 inches long.

I may try them in the big tank as there two fast for my large oscars to mess with. hopefully next week I'll have a 125gallon. that should be completely setup. next month.

07-23-2003, 06:03 PM
gravel trick worked, I guess it was cycleing it cleared up in 48 hours and my nitrates are now safe again.

07-23-2003, 10:42 PM
Good to hear that! :)

07-30-2003, 07:04 PM
Mbuniac......... sorry, I didn't see your question.

Yes, it would be O.K. to vacuum just the top layer of the entire gravel bed, but eventually you'd have to change that program and get all the way to the bottom. I just prefer to completely vacuum a small area at a time. Regardless of one's specific approach, the key is to avoid eliminating all the bacteria.