Topic: NITRITE Level is high =(

[arleneadolfo]

Hi all! Here's the scenario:

I recently purchased a 90gal tank for our office and let it cycle for about 2 weeks and tested the water = everything was good (Jebo tank).

Purchased 4 juvenile oscars (2 tigers, 2 reds) and 2 jack dempseys.  The water was fine until the other day when the nitrite levels suddenly spiked up.  Everything else was fine (nitrate at about 30ppm, hardness at about 200ppm, cholorine at 0ppm, alkalinity at about 180ppm, pH at about 7.8.).  I added Kordon's Amquel Nitrite/Nitrate/Amonia Remover...still no luck.  So my colleague and I did a 25% water exchange yesterday and I tested it again this morning, still no luck.  Algea was growing a lot in the tank, so I placed a pleco in there (he's pretty big). I added a few plants as well....I feel that I shouldn't wait this out since our last tank died from the Amonia being so high (they were peacock cichlids)...so I am scared to wait!!

I know oscars are really dirty fishes...so I tried to clean as much "poop" as I could when I did the water change (we have a sand substrate so I was able to "swirl" the poop out...).  I don't over feed them and I make sure that no food is left floating around after a few minutes.

Any other suggestions???  

[Dale]

Hi ya mate. I can't say that I've ever had any nitrite in my water. It's a tricky one in my eyes because as I understand it your filter turns ammonia into nitrite and then nitrite into nitrate. you're going to have to hold on for one of the experienced guys to give you the real help. What ever info you can give will help you solve it quickly. 30ppm for nitrate is fairly high. How are your fish behaving?
What type of filtration are you using? 

[Stormbringer]

your way overstocked in that tank
you have 4 more fish than you should in a 90 gallon
it also takes more than 2 weeks to cycle a tank (unless you used mature filters or media )how did you cycle the tank ?
also using stuff that takes ammonnia and nitrite out the water could be depriving the filter bacteria of food
when you do a water change do you use dechlorinated water ?
all you can do is big water changes with dechlorinated water of at least 50% every other day or when the nitrite hits .5
what filters are you using and do you know the gph of them ?

[Gerry]

your getting this spike more than likely because your adding fish to soon and to many for for the tank capacity.

Nitrates of 30 are not good either.

water changes are inadequate for a cichlid tank even properly stocked, as you say they are messy buggers.

your 90 gallon will hold two of the 6 fish you have cichlid wise and if you want to keep the plec then with plenty of water changes this is doable (though big plecs don't really do much for algae as they tend to turn to a more veg diet as they grow (assuming you have a common))

[Ezekial]

I agree.  2 weeks isn't really enough time to cycle a tank from scratch and your tank is overstocked for the long term.  Also you probably need to do 50% or greater water changes at least once a week (more as the fish grow). 

[arleneadolfo]

My fish are behaving fine; swimming normally...active...and aggressive eaters.  The filter is the type that sits on top of the tank (not internal, nor canister-type).  There are filter pads and cerramic pieces in there.  The filter pump is  Newport 126 (60hz...20w, Hmax: 0.9m, FLmax 900L/H...if that makes any sense!!)

Am I really over-stocked?  The aquarium "specialist" that sold us the Oscars said "the four should be fine in your 90gal" (he is the same guy that sold us the tank....).  My boss wanted more fish so we got the Jack Dempseys...argg...

Unfortunately, I have been informed that our water is not decholorinated...should I return a couple Oscars...?  

[Dale]

Unfortunately mate It looks like you've come across someone who just wanted to make a good sale no matter how the fish are kept.
  You're water not being dechlorinated is a huge risk to the health/lives of your fish, any good lfs would not have let you walk away without the treatment. Chlorine will not let your tank mature with the bacteria it needs, nor will it or the metals we have in our drinking water do your fish any good.
I would say (if possible) re-home or return the fish and start the cycle of the tank again. Leave it for at least 6 weeks, then maybe introduce one fish for a while and see how you get on.
you basically want your filter to turn over 4x the volume of the tank in an hr to be effective.
like the guys have said two of the six would be plenty, or maybe go for something that doesn't get too big.
PH is a bit high for those cichlids also, around 6.4 i find is ideal.
I hope this is of some help.

[Dale]

Just an after thought.
   For an office setting, a large cichlid tank probably isn't the easiest thing to have as (as you have already found) Oscars can make allot of mess, and trying to keep the tank looking clean and attractive can sometimes take considerable time, and rapidly go down hill with neglect. maybe a couple of dwarf species of cichlids kept with some general community fish would give the tank some color, activity, and be less hassle to maintain.
I used to keep Kribs in a community tank, fun to watch and get a lovely red belly.     

[Gerry]

900 litres is 237 gallon per hour flow from your filter and since you have HOB filtration you want 900 gallons per hour (tank volume x 10)

HOB (hang on back filters) need to turn the tank water over 10 times per hour
Canister filters need to turn the tank water over 5 times an hour as they hold a lot more media


Yes you are way over stocked, think about 4 fish that get 12 - 14" and then 2 that get around 10" and a plec who can get 18 - 24". that is a lot of big fish to be breathing and pooping into 90 gallons without the swimming issue

You can have 2 Oscars, or 2 Dempsey or 1 Oscar and 1 Dempsey in a 90 gallon

[Dale]

900 litres is 237 gallon per hour flow from your filter and since you have HOB filtration you want 900 gallons per hour (tank volume x 10)

HOB (hang on back filters) need to turn the tank water over 10 times per hour
Canister filters need to turn the tank water over 5 times an hour as they hold a lot more media


Yes you are way over stocked, think about 4 fish that get 12 - 14" and then 2 that get around 10" and a plec who can get 18 - 24". that is a lot of big fish to be breathing and pooping into 90 gallons without the swimming issue

You can have 2 Oscars, or 2 Dempsey or 1 Oscar and 1 Dempsey in a 90 gallon

I'm not familiar with HOB filters, I've never actually even seen any for sale down this way. Would I be right in guessing that they aren't overly popular Gerry? Would this sort of filter be effective enough for, a couple of Oscars say?

[Gerry]

they were not available here until recently (see them on the new cube tanks)

Popular in the USA.