Nitrates are too high

[adpgt]

Hello everybody,

my nitrates are around 180-200. The tank has been set up for 1.5 years now and I haven't done any water changes or cleaned the gravel till 2 weeks ago.

From those two weeks to today, i've cleaned the gravel about 5 times and done about 5 25% water changes. I just got the water tested today and the nitrates are still at 180.

What gives?

Could my filter be bad?
What kills the nitrates? The beneficial bacteria?



Tank specs:
55 gallon freshwater
(2) bala sharks (2) glofish (1) pleco (1) long finned black widow tetra (1) three spot gourami (2) albino black widows

Filter is a aqua clear 110 with media that is a couple years old (from previous owner)

[emc7]

nitrates are the end product of the nitrogen cycle. Any organic that goes into the tank: food, algae, plants, fish ends up as nitrate in your water and they only go up and up and up. The longer the tank is set up, the higher they get.

Concentration math. Replace 25% of the water and nitrates only go down 25%. Likely your original numbers were "off the scale" and really more like 300-400.

This is the classic setup for an "old tank syndrome" crash. Where everything was fine for 2 years and then all the fish were dead overnight and the pH was 4.

The fix is a "big clean". Seriously gravel wash, take it out and rinse it in the sink in a colander or use a canister with a "micro filter" until the filter no longer clogs. Replace water in increasing amounts until your nitrates are way down. 25%, then 40%, then 60%, then 95% (fish laying on their sides in the last little bit of water) the fish should get used to new water that way.
Clean (but don't replace) the filter media and all of the filter tubes, scrub the crust off.

[adpgt]

How will the fish get use to the new water if they are on there side?

Should I take the fish out and put them in a bucket till I clean the whole tank or should I just 95% of the water out of the tank and leave the fish in the other 5% and then take the gravel out and clean it?

[Angelclown]

I have a 55 gallon tank. What I usually do if I have an extra 5 gallon bucket is fill the bucket up with the tank water, then catch all my fish and put them in the bucket. Then I deep clean the tank, I take all the water out, that usually gets all the nitrates. Then I fill the tank back up with new water, put in dechlor and then I put the fish back in the tank.

You could do a 50% water change every week until your nitrates go down. But nitrates are not as dangerous as ammonia and nitrite are to fish. I have high nitrates, above 80ppm, and my fish are doing good.

[emc7]

The order doesn't matter. You can put the fish in a bucket, but not if they'll kill each other, jump out, or get too cold. So you need to plan based on what you have. You may need more buckets (buy new and rinse well). When you do a really big water changes, you add the new water back slowly so fish can get used to it, or do water changes of increasing size so the water gets more and more like the new.

The thing is, nitrates don't ever go down on their own, only up. At some point they do become dangerous, but you don't know what point ahead of time.

The "big clean" is an attempt to get out as much "muck, crud" whatever you call the stuff stuck in the substrate that slowly decays and makes more nitrate out of the tank and to get as much nitrate as possible out of the water without shocking the fish. If you do the water w/o the muck, nitrate will climb back faster than they would if you got most of it out.

Once you have most of the nitrates out of the water, and most of the crud out of the tank, you should be able to keep nitrates in check indefinitely by weekly (give or take) water changes. Spot check nitrates every few months and when they start climbing again, do another "big clean". Some tanks need it every 3 months, some 6, 12, or 18. Some lightly stocked tanks can stay in balance for years with partial gravel-washing each water change.

[adpgt]

If I were to deep clean the method, wouldn't that shock the fish as they are use to the 180 nitrates right now? It would be a sudden drop to 50ppm or so and I think that would shock them, correct me if i'm wrong here.

Also, this would restart the nitrogen cycle, correct?

And then should I change my filter out?

[Angelclown]

Keep the filter in. I don't think that the nitrogen cycle would start over completely, you may get a mini cycle, but that is better than a full cycle. I have done a deep clean before and I didn't notice a shock to the fish.

I agree with emc7, if you have fish that will jump out, or whatever, then you will need multiple buckets to do a deep clean.

After doing a deep clean I would keep up with water changes and water testing weekly or twice a month. That way nitrates don't climb as high. I usually do a deep clean once a month or so. I have been letting the tank go and I shouldn't have. I need to get back into taking care of it.

[emc7]

No, don't change your filter. That is what restarts the cycle. Just get as much gunk out as you can without changing it. Keep the media wet and then put it back.

Any sudden change of water can shock the fish. Most fish can deal with buckets, and decor and substrate disturbed. You can put fish in a bucket or leave them in the tank and take the water level down low. Then you slowly add new water while watching how they act. If they are fine for 10 minutes, then you add more new water. If the bucket gets full you take the water level down low and go again. In the tank, you just keep filling it up. The first few additions are the most change. You can speed up as you go along.

[adpgt]

How would the fish act differently? Like how could I tell?

[Angelclown]

If they are acting stressed, swimming eradicately. If you fill too fast it could result in the fish have swim bladder disorder or other things. Take the advice of emc7, because I don't know if your fish are used to getting a big clean with their tank or not. Mine are used to it and I can watch them for stress. I have sensitive fish that are susceptible to diseases but I have to get my nitrates down and keep them down.

I just bought two new 5 gallon buckets so either today or tomorrow I will be doing some deep cleaning. Then I will do weekly water changes so that the nitrates stay down.

[emc7]

Gasping, gills moving fast, laying down, floating belly up. Most of those fish are river fish, so they should deal with wc well. Match the temp or go slightly warmer, Don't forget dechlor.

[Angelclown]

Originally Posted by emc7 Gasping, gills moving fast, laying down, floating belly up. Most of those fish are river fish, so they should deal with wc well. Match the temp or go slightly warmer, Don't forget dechlor.

I agree with this. My fish are used to water changes, but I still do it slowly as to not shock them too much.