Nitrates, Nitrates, Nitrates

FishForums.net Pet of the Month
🐶 POTM Poll is Open! 🦎 Click here to Vote! 🐰

gumshoetortis

New Member
Joined
Mar 2, 2005
Messages
5
Reaction score
0
Greetings,

For some time now, I have been dealing with a nitrate problem in my 125 gallon cichlid tank. I have read as much information available on the subject, discussed the matter with fish store owners and sought the council of other avid fish enthusiasts, without much sucess. In the process of lowering the levels, I have followed all advice, sparing no expense on the tank to rid myself of this headache. New filters, water changes, absorbers and the like, still, I cannot get the nitrates below 200-250 ppm.

Now, there are those who would say that the nitrates are not that big of a deal, and initially, I would agree. I have worked on other tanks the same size with more fish in it with slightly lower nitrates (180 ppm) and observed no obvious effects on the fish. Some sources site that when nitrates remain toxic of a period of time, it can adversely effect the health of the fish...

It is my desire to lower them, not just to have them low, but because there are rising problems in the tank: my jack has slowly stopped eating, my green terror swimming behaviour is odd (he doesn't stay afloat anymore) and two of my jewels have very erradict behaviour, and are losing color. Everything else is in balance (save for the ph, which I cannot get above 7.3, probably because of the nitrates)

I am now at a loss, and any help would be wonderful.
125 gallon tank initially with a eheiem 2256 wet/dry filter.
Added an undergravel plate with three beefy powerheads (aquaclear 80s)
HOB filter for mechanical filtration.

As for the fish, it is an odd mix, but it works (they were raised from babies)

A Large Albino Oscar
A large Jack Dempsey
A large Texas
A large Green Terror
A large Red Terror
A medium Green Terror (male)
2 large coupled Red Forest Jewels (lifallili)
2 meium jewels
2 small jewels
2 small convicts (recently added)
A large pleco
A large chinese algea eater
a fat chocolate catfish
a red tailed shark


Too many fish for the tank? Could it be another problem like hexamite or some other parisitical infection? Is it food I am feeding them?

I negelcted to mention that I clean the water at least two times a week, with a large change (50 to 60%) on the weekend. The day of the water change the fish seem happy, but the next day, up goes the nitrates to off the chart, and zee fish are sluggish...

Thanks.
 
I have a couple of questions:

-Have you tested nitrates from your tap?
-How often do you vac the tank and rinse the filter media?
-What are readings for ammonia and nitrites?
-What is your water's kh?

Yes your tank is overstocked. This is most likely the reason for the problem. Nitrates are the end result of the nitrogen cycle. To produce lots of nitrates, you need to be starting with lots of ammonia. That ammonia comes from the fish waste (and any other organic matter decaying). Your fish load is putting out a ton of ammonia the end result of which is high nitrates.
 
Over feeding wil also help to raise the nitrates (I have also had a problem). I would say not to depend totally on the absorbers, and try to find the root of the problem instead of a patch. Do lots of water changes, test the tap for nitrates (if they are high, switch to RO or bottled water), and lower the amount you feed. I would even say stop feeding for a few days or every other day.
 
Overstocked and Overfeeding were my first two thoughts... and you confirmed the overstocked part. My ammonia/nitrate/nitrite are all high and my PH is low (comes that way out of the tap) in my 125 Gal Cichlid tank. We have a common stock and these fish are simply rough on water quality. I think your water changes are keeping your fish alive. I'd suggest possibly getting another large tank or a couple smaller ones (such as another 75+ Gal or 2 or 3 29+ Gal, because we all know that getting rid of fish isn't an option :p

I question the effectiveness of under gravel filtration when dealing with med - large cichlids. I've heard arguments both ways, but filtering water through poop filled gravel just seems risky to me. With all the care your giving them I'll assume your using a gravel vacuum during your water changes, if not I highly suggest it. Especially with the under gravel filter.

Isn't reducing the amount of food you give them the simplest way to address such problems yet is the hardest to actually do? How can I not throw them a couple crickets or chunks of frozen treats when they look at me with those big brown eyes... but hard as it is... it is important.
 
Sorry but the tank is horrificly over stocked, large Central American Cichlids are messy hearty eaters and should be stocked at one fish per 40 gallons of water, a 125 should certainly have no more than 4 such fish in it.

The wet/dry filter may be adding to the problems, wet/drys are notorious for being victims of their own success as they are so efficient at converting ammonia/nitrite/nitrate that the nitrate levels rise so rapidly that the fish keeper cannot keep up with them via water changes. To make your wet/dry less efficient and so lower the ammount of nitrate created you need to ensure that the flow rate is no more than 5 times tank volume per hour, ie 625 gph. The UGF will certainly not be helping matters and IMO should removed ASAP as organic debries can accumilate under the plate and play havock with water quallity.

After water changes what does the nitrate level fall to? When dealing with large scale nitrate problems it is best to do smallish 25% water changes with a quick vacume every day until the nitrates have fallen to your desired level, usually at around 10ppm above tapwater level. Once this has been achieved the nitrates can be kept low by frequent large water changes (in your case i would recomend 50% twice a week) and the use of nitrate adsorbing filter medias or other nitrate reducing means (deni filters etc). I have personally had good success with KENT nitrate sponge granules.
 
Thank you for your assistance.

As far as the levels in the tank:
the ph is now at 7.3
ammonia = 0
nitrites = 0
tap water is good (no nitrates)

The gravel gets vaccumed in sections, but over all gets cleaned once a week.
I am not sure of the kh.

The fish get fed once a day, and I make sure that there is no left overs. (save for a few morsels, which the pleco gobbles up quickly.)

As far as the ugf, it was just installed about a month ago. After I purchased it, I realized that it wasn't going to assist me in my endeavor. The stand the tank sits on allows me to look underneath the ugf plate, and it is clear/clean, save for some gravel bits...

In regards to the rate of the wet/dry, it cycles really slow @ 277 gallons per hour. I have not as of yet attempted to do 25% water changes per day, but will start doing so.

I have used the nitra-zorb sacks, but find that it is not an efficient way to deal with the issue. They work initially, but quickly become useless, and they cost a lot.

My next plan (after the 25% water-a-day idea) will be to allow the biological grow for the ugf and convert the wet/dry media into a big nitrate abosorber with granules that remove it from the water. I would rather not resort to such measures, being that it would be an expensive way to deal with the nitrates.

It would probably be wiser to invest the cash into another tank and move half of the inhabitants from one to the other...

And the obsession grows... will there be no end?

:D
 
the end is called death where we transfer ourselves to the big Oscar Pond in the sky....
 

Most reactions

trending

Staff online

Members online

Back
Top