Nitrate Level Spike

[tonitetra]

Hey? Hi? wassup? I don’t really know how to start a thread, this is my first one. Anyway, I have a 45 gal planted tank with discus, angel fish, and some guppies. I guess you can call it a nano-tank, but I am offended. Soo it’s about 6 months old. The levels are 0 nitrite, 7.0 ph, and the nitrate levels are at least 70 ppm. I have no idea what cause the nitrate levels to spike. I have had perfect water for a long time, and I do 30% biweekly water changes. I honestly know it’s from over feeding, but I SWEAR TO GOD it say you should feed baby discus at least 12 times a day. Of course I don’t do that but I do feed them twice a day, an mix of blood worms and pellets. I don’t really know what to do. I changed the carbon on my filter and I been doing water changes every two days. I read some horror stores about nitrate levels being to high for to long and killing the fish. So that’s why I’m here— for advise. Let me know if you got any ideas.

 

[Barry Tetra]

Hi and welcome, try do daily 75% water change for 1 week and then you should do 75% weekly water change and feed less.

 

[FallenPepper]

Can we get a pic of the tank by chance?

 

[Essjay]

Nitrate in tanks gets there in one of three ways.
Tap water has high nitrate
Made by the 'filter' bacteria
Adding nitrate containing plant fertiliser.

You can eliminate the first by testing your tap water.
Do you add any plant fertiliser, and if so what is it?
But to be honest, made by the nitrogen cycle sounds the most likely. Overfeeding the fish will lead to a lot of ammonia which is turned into a lot of nitrate, and you admit to over feeding the tank. How old are the discus?

Carbon will not remove nitrate. Water changes are the best way to remove nitrate, but they will only get it down to the same as your tap water.
You can also stop nitrate being made by having lots of live plants in the tank, particularly floating plants. They use ammonia as fertiliser and take it up faster than the bacteria and plants to not turn it into nitrite, then nitrate.

You may also be overstocked. 45 gallons is small for discus. They need a tank at least 4 feet long, and around 65 gallons for just discus with no other fish. This will also add to the nitrate level being so high.

 

[FallenPepper]

Was hoping to get a tank pic to confirm that its overstocked but you you've beaten me too it. Plus probs not enough plants to process all the extra nutrients

 

[seangee]

There are also a couple of other things to consider for their long term health:
Angel fish and discus should not be kept together. Eventually the angel fish will almost certainly kill the discus - even if they appear to be best of friends. If not there will be a great deal of stress.
Angel fish and discus both need soft acidic water. Guppies need hard basic water. These cannot all thrive in the same tank.
The ideal temperature for discus is warmer than the recommended long term temp for guppies. This will shorten their lives.

 

[Byron]

As others have mentioned, we need a lot more data to sort this out, but a few things are obvious. Some of these have been mentioned, but they are critical.

Water changes must be more often and substantial. Once a week is minimum, and change at least half the tank volume and preferably 60-70% each time. This is just basic fish husbandry, regardless of the issues here, and the W/C's will improve the fish health regardless.

Nitrate at 70 ppm is frankly going to poison the discus and angelfish long-term, as cichlids are particularly sensitive to nitrate. If this is a "spike," what was nitrate prior to this, on a regular basis? And we need to know the tap water nitrate reading.

A photo of the tank will help us as mentioned. And seange is right on the mark concerning fish compatibility. The numbers of the discus and angelfish are also crucial here.

 

[tonitetra]

I am planning on upgrading to a larger tank in a couple of months, prolly in November. Maybe a 70 or 80 gallon tank. I do use plant fertilizer, it’s called flourish by seachem. I stopped using it though since it created a lot to algae in the tank. I would like to have more plants but that one’s I have haven’t been doing to great. Hence why I bought the flourish by seachem. Also, I have another 15 gallon tank that I am going to use for the guppies. I will definitely do they 75% water changes for the week, but 75% water changes every week necessary? I usually do 30%, 75% sounds like a lot

 

[tonitetra]

As others have mentioned, we need a lot more data to sort this out, but a few things are obvious. Some of these have been mentioned, but they are critical.

Water changes must be more often and substantial. Once a week is minimum, and change at least half the tank volume and preferably 60-70% each time. This is just basic fish husbandry, regardless of the issues here, and the W/C's will improve the fish health regardless.

Nitrate at 70 ppm is frankly going to poison the discus and angelfish long-term, as cichlids are particularly sensitive to nitrate. If this is a "spike," what was nitrate prior to this, on a regular basis? And we need to know the tap water nitrate reading.

A photo of the tank will help us as mentioned. And seange is right on the mark concerning fish compatibility. The numbers of the discus and angelfish are also crucial here.

Previously the water was perfect. 0 nitrate, 0 nitrite, 7.0 ph, alittle less then 40 ppm kh and my gh is alittle less then 30ppm. Everything has remained the same but the nitrate

 

[Byron]

I am planning on upgrading to a larger tank in a couple of months, prolly in November. Maybe a 70 or 80 gallon tank. I do use plant fertilizer, it’s called flourish by seachem. I stopped using it though since it created a lot to algae in the tank. I would like to have more plants but that one’s I have haven’t been doing to great. Hence why I bought the flourish by seachem. Also, I have another 15 gallon tank that I am going to use for the guppies. I will definitely do they 75% water changes for the week, but 75% water changes every week necessary? I usually do 30%, 75% sounds like a lot

On the water changes, there is plenty of science behind this. Changing close to 70% once each week is minimal. Now, with very few fish and with tons of plants, this can be modified--maybe--but there is still no doubt that the more water changed the healthier the fish will be. There is no filter that can do as much, no matter the size, type or how many; and depending upon the fish load, plants are very limited in their ability to deal with this. There is "stuff" in the water that simply must get removed.

I recall reading some years back that six black neon tetra in a well planted 55 gallon tank could get by with no water changes because the plants would be able to handle the "stuff" that six little fish produce. Most of us have more fish than this.

Discus breeders often change 90-95% of the water in their fry grow-out tanks once, twice, some even three times each day. The fry grow faster and are healthier. That alone shows the benefits of water changes.

Previously the water was perfect. 0 nitrate, 0 nitrite, 7.0 ph, alittle less then 40 ppm kh and my gh is alittle less then 30ppm. Everything has remained the same but the nitrate

I will assume tap water is zero nitrate from this. So that indicates that the water changes have not been adequate. Stocking and feeding also factor in of course; others have mentioned the incompatibility of what is in the tank, and aside from even the basic biological load of the fish mass, the issues surrounding the non-compatibility also impact the biological system. This is because fish under stress have a stronger impact on the system. Fish interact chemically, something we cannot see or measure (test for) and only water changes deal with this. The more you feed the fish the more comes out obviously; as an example, even feeding twice a day compared to once will double the impact on the system. Water changes, fish numbers and compatibility, fish feeding, and cleaning the filter/substrate all factor in when it comes to nitrate.

Another factor is number of shoaling species; here again having too few, even more than too many, can cause trouble for the system. Angelfish and discus are shoaling species. They need groups of five or more, except for a bonded pair for breeding. This too is impacting the biological system.