High Nitrates in chiclid tank...

[Oooops]

Hello,
In October we changed the tank to white sand and large natural rock stacked in the center to give some of the smaller fish some places to hide. We also installed a new Ehiem Pro 3e on our 75 gallon freshwater tank. We ran are old HOB filter on the back along with the new filter for a month and then pulled it. Since then we have had to perform water changes on our tank every week. We bought the Ehiem to help us increase the meantime between changes which was 2 weeks. We were hoping to get to once a month. If we don't change the water once a week we loose fish period. After 1 week the Nitrates are 20 - 30.

My questions are as follows? Could the sand be causing the higher nitrates?

Is it possible that the Ehiem Pro 3e is not do as good of job as the HOB was regarding Nitrates?

The large rocks are some sort of Montana stone brown to purple in color. Could these be causing the high Nitrates?

Could is simply be that because the fish have grown that the Nitrates have increased so much?

Here is the stock list:
Red Zebra Pseudotropheus estherae
Nimbochromis venustus
mloto Likoma
Placidochromis phenochilus
Buddochromis Nototaenia
Dimidiochromis Compressiceps
Maisoni
Usisya Favesant
Red Top Aristo
Protomelas
Yellow labidochromis caeruleus
Lethrinops nyassae
common Brown Pleco
X3 Synodontis petricola

Plant Life:
Java Ferns X5

 

[HarleyK]

Howdy,

Nitrates are not killing your fish. These are not toxic levels.

However, that's a hefty stock list for a "new" tank. What are your nitrite and ammonia levels? pH and temp? Copper? Any medications used?

What filter media are you using (a filter is only as good as the biomedia it holds)?

HarleyK

 

[Oooops]

Just noticed all of my spelling errors including misspelling cichlids...

Basically, the filter is loaded per recomendations here... http://www.eheimasiapacific.com/prod_e_media_setup.html

Our filter media currently:
3l of Eheim substrat pro
2l of Eheim substrat
1l of carbon (just recently added a bag of carbon to see if it would help)
2l of Mech

Nitrite 0
PH 7.8 (we add 2 tablespoons of cichlid salt to get it here)
Amonia 0

Nitrate for tap water is 0

-Kirk

 

[Pharaoh]

FYI. With that stocking, you should be changing you water every week. I would recommend it without that many fish.

If your nitrates are 20-30 are 1 week, then there is nothing you can do besides change water or reduce the amount of fish that you have. It sounds to me that there is one or two things going on.

1. There is too much excess food in the tank that is rotting.
2. Too many fish (too much bio load)

Seems to me that the filter change was just a coincidence. Shouldn't have anything to do with it.

Either get rid of some fish or change the water more often.

 

[Stump]

Readings of 20-30 ppm for nitrates is not toxic. It is an ideal range IMO, though lower is always better. I keep my nitrates below 40 as a limit, and my fish are always fine.

Others will tell you different i'm sure, but unless you are dealing with a particularly sensitive fish, such as discus, or altum angels, these levels are fine IMO. However, weekly water changes at these levels is almost a must.


Please remember, this is just my experience/opinion...

 

[KaiserSousay]

Nitrates are not killing your fish

+1..your levels are pretty normal and well within safe range.
I would lose the charcoal and add more bio media, gives you 6l of bio and 2l of mech.
You didn`t mention your feeding schedule, every day? every other day..could be your HOB was pulling out the uneaten food better than the canister..you could also just need more water movement..spraybar??..powerhead??

you should be changing you water every week

What he said, +1
HTH

 

[FSM]

could be your HOB was pulling out the uneaten food better than the canister..you

that makes no difference; unless he cleans his filter all the time. It doesn't matter if the food decays in the filter or on the sand; it still adds nitrate.

 

[KaiserSousay]

unless he cleans his filter all the time

True enough.
Did that whole assume thing..HOB cartridge=easy change, clean..=done often.

 

[Nic]

remove the carbon... the amount of replacement it needs in a canister means more maintence than needed.... add more bio.... also water changes water changes water changes.....

 

[KaiserSousay]

cleans his filter all the time

True enough. Just did that whole assume thing.
HOB=easy filter clean, change would=done often.
Canister=more effort involved would=done less.
None the less, I do not think nitrate levels are doing the fish in.
Just for drill, Oooops, what are your other water params???