Please Help with high Nitrate levels!

[whiddett]

Hi. I have had my 125 Litre tank for just over a year. It is a juwel Rio125 and so has the Juwel filter system and sponges. I make a 20% water change every 2-3 weeks and replace the Carbon sponge every 6 weeks.
I never usually test my water but last week I got a new 260 Litre tank and decided to buy a test strip kit to monitor the water whilst the filter system matures. So this evening I decided to test the water in my 125 litre tank and found the Nitrate level to be alarmingly high. The test result read as follows:
General Hardness, GH = 180 (Very high but tap water in my area is very high so not alot I can do about this???)
Carbonate hardness, KH = 80 (OK I guess)
PH = 7-7.5 (OK)
Nitrite NO2 = 0 (OK)
Nitrate NO3 = 200+ (Top of test scale!!!!!)

Now when I first got my tank the guy at the fish shop said it was important to change the Carbon sponge as recommended but not to bother changing the other sponges as that would remove the good bacteria. I have therefore never replaced the Green Nitrate removal sponge which juwel recommend to change every 6 weeks! Please could somebody explain to me how the nitrate removal sponge works and if I should be replacing this regularly. Any other advice about my other test readings would also be much appreciated. Your answers on this cannot be too long or too detailed!
The good news is that the fish seem pretty happy still but how long that will continue I dont know....

 

[rich311k]

Forget the sponges, the problem is the 20% water changes every 3 weeks. Sounds like you need to make it some thing like 35 every week. Right now you should do 20% water changes every couple of days until those numbers come back down to a normal level.

You store guys is right I never change sponges, only rinse them until they fall apart.

The hardness is ok. It is better for stable than perfect. Leave it as it is, trying to change it will cause you more problems than it is worth.

 

[whiddett]

So are you saying that replacing the Nitrate removal sponge will not help at all and that it would be a bad idea to do so? Do you know how the Nitrate removal sponge works? Does the sponge absorb the Nitrate or is it bacteria that lives in that sponge which removes/converts Nitrate?

 

[Purrbox]

Rich is spot on with his advise. Your other parameters are fine and don't need to be messed with. Small water changes every other day will bring your Nitrates down slowly while avoiding shocking your fish which will have gotten used to these high levels over time. Once you get your Nitrates down to the 20-40ppm area you'll want to adjust your water change schedule. You can either increase the size of your water changes and/or frequency. Basically if you find that your Nitrates are still climbing then your water changes aren't keeping up and need to be increased.

Also it's important to note that test strips are notoriously inaccurate. I'd recommend purchasing liquid test kits next time around.

 

[rich311k]

It does some kind of chemical removal. Bacteria that eat nitrates are anaerobic and dont do well if an O2 rich enviroment.

You can change the sponge if you want but the fact is the easiest way and the best way for your fish, to reduce nitrates is to change water. There is more than just nitrates removed and replaced when water is changed. Remember fish come from lakes and rivers were the water is replaced continually.

I change water frquently and I think my fish are colorful and healthy and active because of it.

With a level of 200ppm, give or take some, test strips are not that accurate, any new fish you iontroduce is not going to do well and the ones in the tank will be much less resistant to disease.

 

[whiddett]

I used to do 10% water changes weekly but I felt that the fish were stressed by me interferring with them that regularly. Perhaps I will do a few changes over the next couple of weeks and then do bigger bi-weekly water changes.
By the way, when you said you never replace sponges until they fall apart, does that include your carbon sponge?

 

[tawolcott]

I wouldn't worry about the nitrate sponge (replacing, just wash it). The description from the manual implies that it has special bacteria that eats nitrates. Unless something new has come along, nitrate eating bacteria are anerobic and need the absence of oxygen to colonize. That's not happening in a canister. Be different if the claim was absorbing material vrs bacteria

 

[Purrbox]

I used to do 10% water changes weekly but I felt that the fish were stressed by me interferring with them that regularly.

I've actually done 50% or greater water changes on a weekly basis. The fish and shrimp love it. They are always more colorful and active after the water change. It's not at all uncommon for a good sized water change to encourage mating, and I've witnessed this fact with my shrimp on many occations. As long as you match temperatures and dechlorinate the water your fish will appreciate the water change.

 

[rich311k]

I used to do 10% water changes weekly but I felt that the fish were stressed by me interferring with them that regularly. Perhaps I will do a few changes over the next couple of weeks and then do bigger bi-weekly water changes.
By the way, when you said you never replace sponges until they fall apart, does that include your carbon sponge?

I do not use carbon, just leave it in. it has lots of surface area for bacteria growth. The fish will adjust to the water changes. Mine watch me and follow my hands around. I think they are making sure I do it right and that I don't move anything where they do not want it.

 

[whiddett]

I've actually done 50% or greater water changes on a weekly basis. The fish and shrimp love it. They are always more colorful and active after the water change. It's not at all uncommon for a good sized water change to encourage mating, and I've witnessed this fact with my shrimp on many occations. As long as you match temperatures and dechlorinate the water your fish will appreciate the water change.

Its funny you should say that. I transferred my Leopard Danios to my new 260 litre tank as they are hardy and should get the filter system maturing and I'm sure they have been acting quite frisky ever since. Ive not seen any eggs get laid or anything but the Male seems to keep getting close to a big fat female and kind of vibrating against her in the bottom of a large Galleon ornament I have in there. I dunno if they are mating or not but certainly seems that way.

 

[MisticX]

1. replacing water stresses fish
wrong
as long as u habituate them with it (example leave the tubes u use to change water in the tank ... move slowly ...) they actually like it.
this is how i teach my fish to play with my hand, and nowadays i play with them daily.

2. PWC's encourage mating
true
i've seen it a lot with my fish, they mate like crazy after a pwc25%

3. have or not a nitrates down filter
to be honest, if you do pwc's once a week at 10-15% or twice a week at 25-30%, you'd rather add a regular sponge instead of the nitrates down one.
WAY cheaper, and will do perfectly same job.

4. pwc's do not have the SOLE purpose to refresh the nitrates level (lower) but also to remove some of the toxic fish waste that cannot be decomposed but in long term (sulfites sulfates) and that usually decompose themselves directly in so3 (one huge bubble that usually kills everything)


so as my mates here already specified
- i would not use another filter BUT a regular sponge
- i would do PWC's on a regular basis
- i would leave my pwc material in the tank