Nitrate spike

[Princess1982]

Hi All.

I was wondering if you could help me identify a reason for a sudden nitrate spike in my tank. I must confess I have become rather lazy when it comes to testing the aquarium water as for months the tests have been exactly the same. I have not tested for a few weeks but tested this morning and was horrified to notice that the nitrate level was at 80ppm!!

I recently put some new plastic plants in the aquarium but washed them thoroughly in old tank water before adding them. Could this be a reason for the sudden spike? My water has been perfect for months.

I have just done a large water change and the nitrate now sits at 40ppm but obviously this needs to come down further. Are frequent water changes the answer here?

Tank stats

180 litre fluval with 2 filters and 30cm airstone
1 x black moor
1 x red cap
1 x leopard plec
1 x common goldfish
1 x calico ryukin
1 x white ranchu

Water parameters this monring

Ammonia - 0 ppm
Nitrate - 80ppm
Nitrite - 0
PH - 8

I use Prime water conditioner which is supposed to detoxify nitrate. Will this help?

I know the tank is slightly overstocked but I have an additional filter and this has never affected the water parameters before.

Please help!


Many thanks in advance

 

[jlk]

Hi Princess! Your overstocked tank is starting to come back to bite you in the rear. The problem is only going to continue to get worse until you can upgrade their home. Your fish are growing and their ammonia output is steadily increasing. Steadily increasing ammonia equates to steadily increasing nitrates. So far, you have been just lucky-what will happen in the near future is the bioload your fish are producing is going to overwhelm your good bacteria- there is only so much room for them to grow on. This will result in ammonia & nitrite spikes that will likely go undetected until something bad happens.

The solution is a big tank upgrade. Until you can do this, you must step up your water change schedule to try & keep your nitrates under control. Your fish are not going to stop growing or stop producing ammonia. I would not do any less than 50-75% atleast 2-3x per week.

 

[Princess1982]

Oh no! I was hoping it was just the addition of dirty plants

I am looking at getting a larger tank I just thought I had more time. I will give the filter a clean as I am not sure this is working properly either after a quick inspection and will do large water changes to try to get the nitrates down. Best get back on the net and get a larger tank. How many litres would you suggest for the fish I have? I do have a smaller 54 litre tank but I haven't been using it. I was keeping it as a hospital tank.

Mant thanks JLk! Really appreciate your help.

 

[jlk]

As big as you can manage- the bigger, the better! Nothing wrong with your filter. Its doing its job and your bacteria (so far) are keeping up with the amount of ammonia being produced. Its just that steadily increasing nitrates are an indication of a ticking time bomb. You really should consider rehoming the common to a happy pond home. This will help alot because he has the largest growth potential (up to 18inches). The 54l tank really would only be good for a single goldfish fish very short term- if you want to put a fish in this tank, I would put the pleco in this. If you take out the pleco & the common, you would be able to manage this tank for quite awhile comfortably with only four fancies as long as you stay on top of regular water changes. Just an idea!

 

[Princess1982]

Yeh I was think the common should be rehomed. She is a bit of a bully and tends to eat all the food. Cannot possibly part with her though because I have had her years so I will have to put her in the smaller tank. The red cap and the common are about the same size (3 inches in length) and I think are boyfriend and girlfriend lol. They follow eachother everywhere and always have done. Could I put those 2 in the smaller tank for a bit or would it be too much?

 

[ashleynicole]

I have to agree that your bioload is very large. I would keep a watch on places like craigslist for extra tanks. You could always split them up into 2 or 3 different tanks if you don't want one huge tank.

 

[jlk]

The 54l is only a 14g tank. It really is too small for a goldfish except for short term use. Two goldies will be a recipe for disaster in this size tank. Thats why I suggested the pleco for this tank.

 

[ashleynicole]

I wouldn't put any in a "smaller" tank. A goldfish needs at least 20 gallons to itself and then an additional 10 gallons per goldfish or something like that. So you could have 2 goldfish in a 30 gallon tank. 180 liters is about 45 gallons right? so that should sustain a maximum of 3 goldfish. I am not an expert on the different types of goldies but I would say pick 3 to keep in there and get a 30 gallon for 2 of the others maybe?

 

[Princess1982]

I'm now looking to get a tank double the size. Hopefully that will sort out the problem. Thanks for your help. Much appreciated.

 

[ashleynicole]

I'm now looking to get a tank double the size. Hopefully that will sort out the problem. Thanks for your help. Much appreciated.

oh wow i hope you can get a bigger tank It is always nice to be able to upgrade. In the meantime keep up with the water changes to keep your nitrate levels down and prevent disease.

 

[librarygirl]

The common really belongs in a pond, it will get too large for a tank.

 

[rkilling1]

If the NO3 increase was a "spike", then I would not be looking at your stocking. I would be looking for a dead fish, chemical introduced, etc..

If it was your stocking that was the cause, it would not be a spike, but a gradual increase in NO3's.

How often do you perform PWC's and how much water do you change when you do the PWC?

 

[Princess1982]

Well I only have 6 fish and they are all alive. I also have malaysian trumpet snails in the tank but I can never see them. They are always buried in the substrate. Could a dead snail be to blame?

The only chemical I changed is the water conditioner. I now use prime. This allegedly helps with the nitrate. I did put some swimbladder treatment in a few weeks ago. And to be honest I haven't checked the parameters since.

When I do water changes I change about 20% of the water once a week. I have been doing this since the tank cycled which was in November 2011 and the water parameters have always been fine.

I can't say for sure the NO3 didn't gradually build up over the last 4 weeks as I haven't tested the water but before that it was always at 10pppm and has been since November.

I think the redcap would be heartbroken if I gave away the common but I agree she needs a bigger home. I have just ordered a 260 litre tank which I will move them to next week. Lets hope that helps.