Gourami crisis

[Par]

We have a 3" pearl gourami in a community tank which suddenly become lethargic yesterday, gulps air but rests on the bottom, has trouble maintaining vertical orientation, and is ventilating 120/minute.

The tank is 46 gal bowfront set up 3 years ago. Other fish include a 5" tall angelfish, 6" pleco, and 5" red finned shark. A second Pearl gourami died a week ago. The fish all get along. The gouramis were added to the tank about a month ago.

Water quality:
pH 7.6 (same as original degassed tap water)
hardness - very soft mountain water (limits of detection)
ammonia 0
nitite 0
nitrate 200 mg/L
salt 1.2 ppt

The tank was set up 3 years ago. 5 months ago everything was cleaned, but 80% of the water was reused. Filtration is by a Magnum H.O.T external cannister, with two airstones to increase aeration. Water changes have been neglected, obviously. I've vacuumed the gravel and replace 20% of the water yesterday.

Have been feeding TetraMin tropical flakes, with frozen brine shrimp 1-2 times/week.

Is high nitrate sufficient to explain the symptoms?

Any last ditch measures or treatments to try? I have some malachite green?

Thanks for your help.

 

[Brad S]

First, I would re-test your water and then do an 80% water change immediately afterwards. You can't change the water too much so I'd do it just in case. We need some more information to help so let me ask a few questions.

How often do you do PWC's and how much? What kind of water test kit do you use? How old is it? Are you sure of your readings? ie:Yout Nitrate reading of 200 mg/L which is 200 ppm is totally off the scale and I know your reading said ammonia was "0" but it sounds very much like Ammonia poisoning so... Do you/did you clean your canister filter lately? If you haven't, now would be a good time. note: toxins build up in filters and even if you do a PWC, they are still in the filter.

Oh and high Nitrate levels are bad news but I'm not positive what the long term affects are. I've heard it depletes blood oxygen levels and can kill a fish though.

 

[Par]

Hi Brad-

First of all, the last gourami died this morning. At this point my follow-up will concern rectifying the health of the tank for the rest of the inhabitants.

I used "Nutrafin" ammonia (liquid test). I'm pretty confident of my ammonia readings-I've tested it against dilutions of ammonia and they check out. I also diluted tank water and retested to confirm the high nitrate value.

I've neglected regular water changes. I use cold-only tap water, purged with air until I get a negative chlorine read. At this point I can only make about 5 gallons every 4 hours. That's one reason I haven't done more aggressive water changes in the past 24 hours.

Another reason I have taken it a little slow is I'm a little concerned about making the tank too clean too fast, causing an ammonia spike. Any thoughts on that?

I'm interested in any study reports on nitrate tolerance in tropical fishes, if any other readers can link me to some.

Thanks!

 

[mfdrookie516]

simply doing pwc's wont cause the tank to mini cycle unless youre adding water with chlorine in it....

 

[Brad S]

Sorry to hear about your loss. It's always sad. Anyway, you're using a liquid test kit which is good. My main concern is with the paper test strips which are notoriously inaccurate. No problem there though. All your readings looked good except the Nitrates so maybe that's what happened. I guess water change is the answer there. Ammonia spikes. Hmmm, over feeding can cause that. Maybe putting too many new fish in at once. I think the key is anything that abruptly changes water conditions. Ammonia spikes from water changes though... Seems like I remember somebody saying something about that once but it might not have been about ammonia. Don't remember. I do 75% changes all the time and I've never had a problem. Doesn't mean it couldn't happen I suppose. I'll keep looking into it and if I find anything I'll let you know.

Again, I'm sorry about your loss. Brad

Here's a link about nitrate

Aquaworld Aquarium - The Adverse Affect of Nitrate on the Aquarium

 

[Par]

Thanks!