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bigpapaboots

Jack Dempsey
MFK Member
Dec 21, 2012
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Richmond, Virginia
I have a pacu I've had for over 30 years. He's in a 250 gal deep dimension with a 70 gal sump with all the bio balls the sump can handle. Anyway, after this last water change, I've had a bit of a ammonia spike. Currently around .2. (Note that's .2 and not 2) Not bad, but enough to smell that sickening smell. First time I've had this in a number of years. I either overcleaned, took too much water out, or didn't condition well enough during the process. I just did a small water swap to try and bring it down until the bio filter can catch up. Only around 15 to 20 gallons. I was hesitant to do that because didn't want to make things worse. This is a mature tank, been up roughly ten years and have never had this issue. My questions are has anyone experienced anything similar and is this a matter or waiting it out till the filter re-establishes itself? I'm guessing the latter but thought I'd ask.

As for the fish, he seems fine. Not distressed, no rapid gills, and no burns. Though I can't imagine that would happen at .2. Just trying to be proactive for the love of this beast. lol
 
bigpapaboots said:
I have a pacu I've had for over 30 years. He's in a 250 gal deep dimension with a 70 gal sump with all the bio balls the sump can handle. Anyway, after this last water change, I've had a bit of a ammonia spike. Currently around .2. (Note that's .2 and not 2) Not bad, but enough to smell that sickening smell. First time I've had this in a number of years. I either overcleaned, took too much water out, or didn't condition well enough during the process. I just did a small water swap to try and bring it down until the bio filter can catch up. Only around 15 to 20 gallons. I was hesitant to do that because didn't want to make things worse. This is a mature tank, been up roughly ten years and have never had this issue. My questions are has anyone experienced anything similar and is this a matter or waiting it out till the filter re-establishes itself? I'm guessing the latter but thought I'd ask.

As for the fish, he seems fine. Not distressed, no rapid gills, and no burns. Though I can't imagine that would happen at .2. Just trying to be proactive for the love of this beast. lol
Click to expand...

Personally, I would do a bigger water change anywhere along the lines of 50%-80%, and if the tank doesn't settle down, I would take out your pacu and put him in a separate bucket/bin with fresh dechlorinated water in it. Do you have anything else in the tank or just the pacu?
 
pacu mom pacu mom
What is your usual water change rate? Doing lots of big changes is fine, but if you don’t frequently do so, you can shock the system with a big change.
For now, add aeration and continue monitoring parameters. Water change as necessary.
Keeping a pacu that long though, I’d keep doing what your doing.
 
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Congrats on keeping your pacu for over 30 years. I've only had my pacu for 18 years. The only time we had an ammonia spike (besides the time I was stupid and placed them in a new tank with new filters with uncycled media and nearly killed them) was when I fed them copious amounts of watermelon - as much as they wanted to eat. I would change out enough water (do as many water changes as necessary) to remove all the ammonia. I would also dose liberally with a biological additive to correct the mini cycle your tank is undergoing. Do daily water testing and water changes. You cannot change out too much water.

Pacu are more sensitive to nitrogen products than their counterparts in the wild. Any nitrite, and my pacu would gasp until all nitrites were removed. About a year ago, I discovered that nitrates also impact them negatively. Forget about 20 ppm - my pacu look better if the nitrates are less than 5. I have the longest tank upgrade in the history of fish forums so my pacu are still stuck in the way too small 300 gallon tank. I do three to six 30% water changes every day to get the nitrates as low as possible. Can't take out more than 30%, or the pacu are swimming on their sides trying to keep their dorsal fins in the water. Nitrates were 5.6 ppm today, so did 3 back to back water changes. Their color is a lot better with very low nitrates. After a 6 year hiatus, I am back working on their big tank. I desperately need the big tank done - the water changes are killing me on the small tank.
 
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bigpapaboots said:
I have a pacu I've had for over 30 years. He's in a 250 gal deep dimension with a 70 gal sump with all the bio balls the sump can handle. Anyway, after this last water change, I've had a bit of a ammonia spike. Currently around .2. (Note that's .2 and not 2) Not bad, but enough to smell that sickening smell. First time I've had this in a number of years. I either overcleaned, took too much water out, or didn't condition well enough during the process. I just did a small water swap to try and bring it down until the bio filter can catch up. Only around 15 to 20 gallons. I was hesitant to do that because didn't want to make things worse. This is a mature tank, been up roughly ten years and have never had this issue. My questions are has anyone experienced anything similar and is this a matter or waiting it out till the filter re-establishes itself? I'm guessing the latter but thought I'd ask.

As for the fish, he seems fine. Not distressed, no rapid gills, and no burns. Though I can't imagine that would happen at .2. Just trying to be proactive for the love of this beast. lol
Click to expand...
faced the same thing a few days ago. replaced the entire filter media which caused a amonia spike. my pacu seemed a bit stressed and so in order to deal with the problem, i allowed algae to flourish in my pond, which took care of ammonia, while my beneficial media established in my tank. it worked like a charm
 
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I'll post some pics here, just taken. Photos don't do him justice. Looks small to me in the photos, even normal. lol I'd guess he's easily over 2 feet, but the most impressive thing is his girth width-wise. About 5 or 6 inches across.

As for the change rate, nothing unusual there. Same schedule, once every 28 days like clockwork. A media rinse in aquarium water and run crushed coral in sump along with a Nitra Zorb bag a week before the water change. By the way, the crushed coral doesn't help much. He still runs acidic. I might change the Nitra Zorb bag based on a comment above. Can't hurt. Tank smells better, less free ammonia smell. However, I ran a test and it seems to have gone up a bit, around .4. Worried the change yesterday may have unsettled the filter a bit. Think I'll hit him with 2 or 3 caps of Prime and see how it looks tomorrow. Test could be reading ammonium since the tank seems to smell less toxic. Still no distress. Same ole pac man.

I had an awful new tank cycle when I first set this tank up years ago, so I know the worst of it. This is nowhere near that, but don't it to progress, and don't want to overreact and make things worse. Helluva thing. IMG_20231218_145514564_HDR.jpgIMG_20231218_145521519_HDR.jpgIMG_20231218_145521519_HDR.jpgIMG_20231218_145538770_HDR.jpg

Anyway, thanks for your comments. I'll keep you posted.
 
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And Pacu Mom, I know exactly what you're talking about. He started out in a 30 gal, then 70 gal, then 125 corner tank. In the corner tank, I had to do water changes every few days come hell or high water (pun intended) just to keep him alive. I eventually made this jump to the deep dimension and things have settled down until recently. The tank is 5' across x 3' deep. The 3' really makes a diff because he can actually make a turn and swim a bit.

Funny thing is, I got him in 1991. I remember that because I remember doing a water change in his first 30 gal and I stopped to check out a new vid that had just come out - Nirvana, Smells like Teen Spirit. True story. Now I have low spirits because smells like free ammonia. lol

Good luck with your bigger tank. Fingers crossed all goes well.
 
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