My nitrAtes have been high in both my tanks for months now. No ammonia or nitrItes are present. I moved to MN and there is a trace amount of nitrAte in the tap, about 5. Would this keep my levels high or shouldn't it matter as long as Im doing regular water changes? My poor fish don't look so hot and I've lost a few. Some of them are bottom sitting and others are floating at the top (SBDish). Ive been doing water changes every other day for about a month and I've gotten the level a bit lower but the test tube is always red. What can I do besides a total water change?

I have similar probs. I find the nitrates seem to collect in the filter media and I have had to actually replace all the sponge media over the last few months. Water changes just weren't cutting it for me. I put new ones under the old for afew days and threw out disintegrating pieces- totally new media in now- I just stopped being so careful about bumping the cycle. But I dont know if you've just moved -the cycle is not so old so maybe thats not the right advice for your set up..nitrates are so tiresome

I bought filter media called Nitrazorb (spelling ?). I had battled nitrates for a year and this finally got me some results. I also put some plants in the tank. The goldies pick at them but not to the point of destryoing them. Both of these things have really brought down my nitrate levels...finally!

Nitrates, by and large, are the end result of the nitrogen cycle. If you have, for example, x parts ammonia - it will process into y parts nitrite, which will translate to z parts nitrate .

If you have a given number of fish that are fed a specific amount of food each week, they will produce a given amount of ammonia that is transformed into the nitrates. With a regular routine, this amount of nitrate that is produced each week will be appoximately the same, each week.

If you change less water than it takes to dilute that amount of nitrate to at least the same concentration it was at BEFORE the week began, you will get nitrate "creep" - where, each week, your nitrate values will rise. After a number of weeks, you will find that you have ENORMOUS amounts of nitrate in the tank.

TO change this problem, you need to adjust the way you care for your tank. You need to do one of two things:

1. Lower the production of ammonia/nitrite/nitrate by: a. HAving less fish in the tank. b. Having larger water volume for the same number of fish. c. Feeding the fish less food.

2. Changing out the water either more often or in greater amounts at each change.

Cleaning your filter pads mid-week will help - for waste collects in the mechanical filter. If you rinse away that waste BEFORE it is transformed by the BB into nitrite/nitrate, you can avoid that extra nitrate. Eliminating the gravel bottom of the tank can help - gravel, no matter how well you clean it, holds a lot of waste that eventually is all transformed into nitrates. Live plants are a toss - up. They help with the nitrates - some more than others - but if your fish are constantly tearing them to pieces and creating waste - as well as feeding constantly - they produce, in the long run, more waste/ammonia/nitrite/nitrate than they reduce.

I suggest you do a very large water change to bring the nitrate down to the level where you wish it to be at the end of the water change - for example 20ppm. Then test your water just before you would regularly do a water change. CAlculate out how much nitrate is generated in your tank during that time period.

For example: If your tank was at 20ppm nitrates on SAturday after a change, then measure the nitrates next Saturday. Let's say you measure them now, at 40ppm. That means that you have to remove at least 20ppm nitrates in your water change to bring it back down to 20ppm after the change. This is 50% of the water - so you need to change out half the water. If you find that you have more nitrates, you need to change more water

If changing more water at each change is not possible, you can change more often (every 4 days or whatever you wish), feed less, stock the tank less.

This will prevent the nitrates from creeping up.

When I was having this problem, I started rinsing my floss filters daily with tap water, and that helped.

Everything daryl said is very valuable and correct. I just want to add specifically that 5 ppm in the tap water shouldn't be a problem at all. It may mean you need more frequent or bigger water changes, but that's a very low level and isn't unreasoanble or unusual. You didn't say, however, what the nitrate level is in your tank. If its less than 40 (and particularly less than 20), then nitrates probably are not the problem (sensitivity varies by individual fish).

Other things that come to mind for someone who just moved, is that perhaps the act of moving was stressful enough to do in some of your fish. Alternately, perhaps the issue is your new tap water, but perhaps its because locally they use chloramines (not chlorine) to disinfect the water. If you're used to allowing your water to sit out for a day or so to get rid of the chlorine, this will *not* be enough for chloramine. Or, if you didn't even do that before, perhaps the chlorine level in your old place was very low, and here its more substantial.

You can find out about chlorine/chloramine was calling your local water company and checking out your water stats would should be posted on their website. There can also be other harmful things in the water that vary from place to place, like heavy metals. Either way, its a good idea to use some basic water conditioner (even in small doses) to make sure you get rid of those kinds of things. Prime is most popular around here, although I'm a bigger fan of AmQuel+ (although you'll need it in combination with NovAqua+ to do a complete job including heavy metals). Check out the 'water conditioners' pinned thread at the top of this forum for more infomation.


Overall, if the nitrates in the water are high, get them down (5 is not high), but do be aware of other issues as well.

That's a good tip...can't believe I never thought of that one before

Thank you all for the information! Its been a great help and something to get me going in the right direction! I never had this bad of a problem in NY, and there I was stocked even more! I will do a big water change immedietely. I do use Prime at every water change. I just cleaned both filters (in old tank water, of course!) a couple weeks ago, 2 days apart(I have 2 filters on each tank). I didnt realize I had to do this more often. I feed the fish once a day since this has been happening.

Is it better to rinse one filter at a time or can I do both at once?

Off to water change I go!

FYI, Seachem (the makers or Prime) told me:


So for a day or two, it will make these things non-toxic, but after that it will be like you never put the Prime in. Prime is a good temporary fix, but not a permanent one. That might explain why the increase appears to be so large.

Novalek (makers of AmQuel+) told me in writing, on the other hand, that the effects of AmQuel+ are permanent and irreversible:



This doesn't eliminate the need for water changes, because of course more nitrate will form, but its not temporary in the way that Prime is. I'd always recommend being cautious in a change of water conditioners, but it may be worth a try. Whatever you do though, water changes are your #1 biggest friend (although a pain).

Ok, good to know. Funny thing is, the store didnt have Prime last time so I did get Amquel+ and I am using it for this water change. Fingers crossed!

Just a thought, does driftwood have anything to do with nitrates? I just thought of the fact that both tanks have some!

Are you saying that regular water changes and Prime/AmQuel is not keeping nitrates in a reasonable range (below 30 ppm or so)?

If your water has 80 ppm, and you do a 50% water change with nitrate-free tap water, it should drop to 40 ppm. If you water has 5 ppm nitrates, instead it would drop to 42.5 ppm. At that level, that'd be very hard to tell the difference.

At a lower level, water with 10 ppm and a 50% change with nitrate-less water would end at 5 ppm. While with 5 ppm tap, you'd end up at 7.5 ppm. That difference should be seeable on a test kit, but at that level, its probably not a big deal anyway.


You said you are doing every-other-day-water changes, but what percentage? 5-10% Or are you talking 25-50%?

If you're doing large regular changes and you still get high nitrates, I have to wonder if your tank is just overcrowded (did you say anywhere what gallon size and # of fish) - so you can't keep up with the amounts being produced.. You should have generally at least 10 gallons per fancy goldfish and 20 gallons per comet/common goldfish.


Finally, you said the test kit keeps coming back 'red'? What level (ppm or mg/L) is that? Which test kit is it? Have you tried another test kit?


If you could give us some more specific #s/details, we may be able to take a more intelligent look at the situation. Just to recap, those numbers are:
- What ppm (or mg/L) concentration of nitrates is your tank actually measuring?
- Which test kit do you use?
- What size tank do you have in gallons?
- What percentage of the water are you replacing when you talk about a water change?
- What is the nitrate measurement 10-30 minutes after the water change?
- What is it back to before the next one?
- How many fish do you have in the tank and what types?

Just to let you know Ive been keeping fish for several years so Im not a "newbie". I havent had these nitrAte problems until moving to Minnesota. I know all the "rules of thumb", ect.

To answer your questions,
My nitrates in each tank were 50+, then 30+, now down to 20 or so. So it has been dropping but still seems to rise too quickly.
I use the API master test kit. With the test tubes and drops.
One tank is 75g and the other 90.
I was doing 1/4-1/3 of the tank in water changes. Since I started this thread, I did a 50% change and today a 1/3 change again.
I will have to test the measurement right after changing water. I dont usually test until a few hours later.
I have 7 fish in the 75g ranging from 2" to 8". All are fancy goldfish(double tailed).
I have 8 fish in the 90g ranging from 2" to 7". Fancies as well.

I was curious as to whether or not the driftwood may be causing a problem? Such as if it starts to deteriorate.

Oh yes hun wood if its old can cause nitrates in the tank.
Do you have nitrates in the water that you change with hun?

just trying to get an idea of this tank

whats the filters and how many gals is the tank?

50+ isn't horrible. Its high and should be brought down, but when we were having a problem with our common in a too small tank, the nitrAtes were at 150-200+ initially. 20-30 is okay, but you shouldn't have to do daily water changes to keep it there, of course.

I didn't know about the wood answer, so I didn't answer it, but glad koko chimed in. Seems that's worth taking out and watching the result.




A few hours later is fine. The real question I was trying to get answers there is how many ppm does it increase per day? By saying 10-30 minutes I just didn't want you to take it 5 seconds later before its mixed up and maybe get a cleaner or dirtier patch. I also couldn't tell your experience level, so I apologize if I appeared to be 'talking down' at all - sorry!


I'm left-brained, so the reason I ask if because by knowing the frequency of the change, the % amount of the change, and the increase per day, you can get a good estimate as to what the nitrate levels should be showing.

I'll take corrections if I'm wrong on this math, but I believe the formula for where your nitrates should settle is the increase between changes divided by the fraction water change you do.

For instance, if it jumps 5 ppm per day, and you do a weekly water change of 50%, then it goes up 35 ppm between changes. It should settle at 35/.5 = 70 ppm (i.e. vary between 35 and up to 70 right before the change).

If it goes up 2 ppm/day and you do weekly 25% changes, that is 14 ppm/.25 = 56 ppm.


This assumes nitrAte free tap - but a bit of nitrAtes there make only a small difference - and also assumes no water conditioner which eliminates nitrAtes (which can make a big positive difference). But it should be a decent estimate.


Based on koko's knowledge though, it seems the first step would be the remove the wood. I learned something new too!

I wonder something, do you have plants in there hun? Plants would help keep the nitrates down a little bit, good plant for a goldfish tank is the Anubis plant, they wont eat it and its a very hardy plant willing to take up some nitrates for you

Koko is right. Real wood, being biological, will break down into waste that forms ammonia. That ammonia will be processed through your nitrogen cycle into nitrates. IF your wood is not NEW it could be starting to break down - and starting to release waste. This may be the reason why your nitrates are climbing where they have not before. Good catch.

Oh cool, and it's a low light plant too. I'll have to try those. Some of my plants just get too messy, or the fish eat so much of it, it disappears quickly.

Thank you everyone for the comments and help! I will look into the plants, however, I have barebottom tanks. Do they need to be planted? I could put them into containers and sink them to the bottom. I will take out the wood tonight and do another water change and see what happens. Seems that my nitrate stayed about the same from yesterday, around 20ppm. The driftwood is not new, but I havent had it for more than a year! I do notice though when I move it, pieces fall off.

The tanks are 75 and 90g Koko with 2 Aquaclear 110's each. I have about 5ppm nitrate in my tap water.

I have had bad times when I had wood in the tank, so yeah get it out.
Now the plants are easy, the best one for goldies are Anubis plants. with those you can let them float or you can if its a small plant, get a tara cotta pot and some river rocks to hold the roots down, dont cover the big hard root just the small ones that come off the big one

Thanks Koko! I have removed all but one small piece of wood. I will order some Anubias after Xmas!

Any time. The best way to get a good deal on them is get the bigger ones, then you can cut the big root and you have more than one in the tank. I would get ones that were so big they came in a black bucket like from a garden place. then I would take them out of there buckets and cut the big root and would have three in the tank cost of it was about 20 usa dollars.

Thanks for the tip! I will definitely check out a garden center.

The difference that plants make is amazing, I only added them a couple of months ago and my nitrates are steadily low now. I can't beleive it took me so long to get them!