I need help for my girl! 27 year old Pacu

Steven's Pacu

Exodon
MFK Member
Sep 27, 2019
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58
Fair Haven VT
As usual, Viktor's practical approach makes good sense. The idea of using the inch-per-gallon "rule" with any fish much bigger than an inch is scary.

Just one point to mention here: this fish is, by any standards, a very senior animal. Like all seniors...people, dogs, cats, whatever...she is likely not as vital as she once was, with reduced immune response and generally not as resilient or quick to heal/bounce back from any stress or trauma. I wonder what the average maximum lifespan of a Pacu is in the wild. For that matter...I wonder if anyone knows.

I won't even hazard a guess as to the lifespan in captivity, because virtually nobody has the facilities, commitment or experience to keep such large fish. The vast majority of truly monster fish like this are purchased, owned and live out their unnaturally shortened lives in tanks their owners consider "big"...100, 200, 300 gallons...and die long before their time simply due to stress-induced disease when they grow large enough to overwhelm the carrying capacity of their tanks, or to overwhelm the water-change capacity of their owners.

You've learned a lot in 27 years and have done an amazing job of keeping this fish. You are likely more qualified to answer questions than most of us; you did a lot of things right to get to where you are now. As fish grow they sort of sneak up on you; that which has worked for years eventually becomes inadequate when the fish achieves a large enough size, but when you see and interact with the fish daily you become almost blind to its increasing biomass and it becomes easy to overlook it.

Fish are not immortal; even under perfect conditions, they live out their lives and eventually die. If you can keep any fish, and most especially a monster like this, long enough for it to pass away of natural causes..."old age"...you have nothing to apologize for...and the vast majority of aquarists will never achieve this.
I want to thank you so much for such
 

Steven's Pacu

Exodon
MFK Member
Sep 27, 2019
21
27
21
58
Fair Haven VT
Welcome to the MFK!

Congratulations on keeping your pacu for 27 years. It is quite a remarkable achievement!

Sounds like you know a lot but need a bit of guidance.

Most usually an illness results from stress. Must ID and eliminate the source of stress. If the illness is in the acute phase, must treat too but again should have at least a good guess at diagnosis, not treat blindly. Mela and Pima are mild antiseptics while, if the ich is the correct diagnosis, it is an external parasite. No logic here.

SP: cloudy water usually means trouble with the nitrifying bacteria,
TBTB: it does often when the system is cycling, yes, but in your case it could be simply the medication

SP: and worried about oxygen
TBTB: yes, mela and pima deplete oxygen, usually when people use these, they add aeration / stirring. half the peers don't believe mela and pima do anything, half thinks it does something.

SP: with her swollen lips.
TBTB: i dont see a link of the lips with oxygen

SP: Her spots are gone, but seems more agitated today.
TBTB: stress

SP: I can continue with both Pima and Melafix,
TBTB: diagnosis or a good guess first

SP: I know water quality is where this begins
TBTB: YES! good job.

SP: It's so frustrating trying to figure it out
TBTB: it doesn't have to be

SP: Temp, ph, nitrifying bacteria, ammonia, nitrites, nitrites, filtration, particulates, media, oxygen, sunlight, water hardness,
TBTB: temp is trivial, pH not important except MUST be stable, NH3 NO2 NO3 is basics, particulates are totally irrelevant except for your viewing pleasure, oxygen is critical but trivial, lighting is of 10th importance, water hardness is trivial

SP: I'll see if I can figure out photos
TBTB: button in the left bottom corner of the reply window says attach files

SP: Would you suggest every two weeks for water changes, or test more for an as needed guide?
TBTB: I'd suggest 50%+ daily until the fish is healthy and 50% weekly or more from there

SP: I'm always worried about losing nitrifying bacteria with too much siphoning, too many water changes
TBTB: these do not affect nitrifying bacteria, they live on surfaces, not in the water column, they live ON you filter media

SP: or filter cleans. I
TBTB: that is a valid worry, you dont want to clean out filter too often, nor too infrequent, now having two canister filters it should be a charm - do one at a time, stagger; most important thing with canister filters is that water entering them MUST be as aerated as possible in your tank, best if drawn from the surface, not from the bottom of a largely stagnant tank or from a dead spot, that'd be terrible

SP: I've added nitrifying bacteria a handful of times after ammonia spiked, but it didn't seem to help. Actually the reverse a few times. Lots of factors to that maybe? Types of bacteria, water changes etc.
TBTB: NBs need long time to settle and start growing, what you added were seeds, it takes time to grow and the right conditions, one of the most overlooked is the oxygen, NBs need oxygen, the more, the better they will work for you, which is why wet-dry, biowheel, shower type filters are in general 10x more efficient per volume of media vs canisters, HOB, barrel, bucket filters etc.

SP: the tank was too small. Equivalent to us standing in a closet!
TBTB: good thinking

SP: Everywhere that I've read online, following inch of fish to gallons of water,
TBTB: This is for guppies and bettas

SP: says 500 gallons is sufficient. I have a friend who builds ponds, and has many carp outside, then inside. He's offered to help me build a bigger tank. Do you have thoughts on how many gallons would make her happy, but not too many, if that makes sense?
TBTB: for large fish it is 1 cubic inch per gallon, so say you pacu is 36" long 18" tall and crudely on average 3" wide = 1944 cubic inches! = need 2000 gal of water. and this is minimum. More is better. I may be off by a factor of 2, maybe she is only 1000 cubic inches, it is still 2x more than what you have now. again minimum.. so for comfort double the minimum, come back to the same 2000 gal that's roughly a 12ft x 3ft round above ground pool, cheap too. even vinyl liner will suffice if no folds , no creases, otherwise she will bite them up and make million holes.

HTH.
That's an Awesome idea! 🤩 what used to be a really pretty dining room is now most definitely the fish room. Dining room table covered with plants and fish stuff. The table can go, then lots of room for a pool! 😃
 
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thebiggerthebetter

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installing 4x4s in the basement to support the floor up is a good idea and should work if it is winged / engineered correctly. 12ft diameter pool will distribute the pressure and weight nicely but someone with some idea / experience in building structural things should evaluate how many floor jacks and where to install. It's better to use more than needed than otherwise, and make sure the supports are out of water or high humidity so they do not rot; it'd be a bad idea to use pressure treated wood in the basement, these are only for outdoor and semi-outdoor applications. Or maybe metal studs could work. Again, as this CAN be highly dangerous to you and your house, I cannot in good faith encourage you to wing it yourself.

Cover will need to be thought through otherwise your house may be too humid, although a dehumidifier needs little electric and can totally mitigate the issue. Your other pets need to be secured from checking out the pool and falling into it, etc. Common sense, sorry.
 
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Steven's Pacu

Exodon
MFK Member
Sep 27, 2019
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Fair Haven VT
I absolutely love you right now for such thoughtful credit! 🙏 Listening to all of you is wonderful because of your clarity. I'm definitely not there, but hang on your words like a kid in a candy shop! Bonnie has survived so far because she loves us, and knows that I'm trying really hard if nothing else. She wants to be here, and chooses to stay. I keep telling her that we're going to beat Buttkiss (named after football player Dick Butkus) who lived until 43 I think? I'm going to try and post shorter videos than my original in hopes you can see her better this way. She looks awful with the bright lights on her! The tank is normally so dark, but the bright lights show her yellowish , and like the tock man on the fabulous 4. 😳
 

Steven's Pacu

Exodon
MFK Member
Sep 27, 2019
21
27
21
58
Fair Haven VT
installing 4x4s in the basement to support the floor up is a good idea and should work if it is winged / engineered correctly. 12ft diameter pool will distribute the pressure and weight nicely but someone with some idea / experience in building structural things should evaluate how many floor jacks and where to install. It's better to use more than needed than otherwise, and make sure the supports are out of water or high humidity so they do not rot; it'd be a bad idea to use pressure treated wood in the basement, these are only for outdoor and semi-outdoor applications. Or maybe metal studs could work. Again, as this CAN be highly dangerous to you and your house, I cannot in good faith encourage you to wing it yourself.

Cover will need to be thought through otherwise your house may be too humid, although a dehumidifier needs little electric and can totally mitigate the issue. Your other pets need to be secured from checking out the pool and falling into it, etc. Common sense, sorry.
Excellent thinking. You sound like an engineer. I do have a contractor friend who I'll bet would come and check it out/ advise at the least! Thank you for thinking of the other animals as well. I'm lucky that my dining room has glass doors at each entrance, so can stay closed. I have a ceiling fan that needs to be installed for the volume of water I have now, so a dehumidifier is a great idea with a bigger tank! 👍
 
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pacu mom

Goliath Tigerfish
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That's a first :O I'd hope they were Brazil aquatic documentaries... because Cat in a Hat and Alice in Wonderland would go way over Bonnie's head. I can't even wrap my head around them :)

pacu mom pacu mom Susan, helpful tips here :)

On a serious note, pacu IQ is scary high for a fish. That's true. And regrettably makes them one of the most horrible tank mates because they know how to take advantage of tank mates often injuring them or even killing them when eating their fins, barbels, anything that sticks out and fits in their mouth. The beauty of giving Bonnie 2000 gal of water at least is you can add some more tank mates but be careful how you choose them and ask us for an advice, the fish collectors who do keep large pacu will be able to advise you well.
Sorry, first time I've seen this thread. Very amazing to have nitrates at 40 ppm with a 30% water change once a month. You must be doing some things right to keep your pacu alive for 27 years. I've only had my pacu for 17 1/2 yrs. Pacu are very sensitive to nitrogen products. Any ammonia or nitrite in the water, and my pacu would gasp. Change out enough water so there is no ammonia or nitrite (if there is any), even if you have to do several water changes. After fishless cycling my current tank, the only time I had an ammonia reading was when I fed the pacu copious, unlimited amounts of watermelon. Pacu are extremely messy eaters, and their water can quickly get fouled with food debris. My pacu get fed an exclusive diet of algae wafers to keep the water cleaner as their big tank is still not ready for them. Amping up your mechanical filtration should help with clarity and doing more water changes. My experience is that you cannot do too many water changes when it comes to pacus.

I belong to a pacu forum on Facebook. Some of the members write that enlarged lower lips is an oxygenation problem, and increasing aeration in the tank will help.

There was a time that I knew the names of many medications and what conditions they were used for. I run a UV sterilizer on the tank, and will never ever run a tank without one. The redox potential boosts fish immune systems. I haven't had any fish medications for 15 or 16 years.

I discovered this summer that my pacu do best with lower nitrates. I keep nitrates below 10 and change enough water to get nitrates between 0 - 3 ppm. If the nitrates get to 20 ppm, one of my pacus just doesn't look well. I do daily multiple water changes.

I noticed a lot of bubbles in your pictures. Could be an excess of protein debris in the water. The only fresh water protein skimmer I know of is Clarity CL-3. However, there are DIY foam fractionators, and duanes duanes is an expert on that.

To summarize:
- increase mechanical filtration
- consider just feeding algae wafers until your pacu is in bigger housing
- more aeration
- consider an UV sterilizer (I have a 40W UV sterilizer on the return end of an FX-6) UV sterilizers are peace of mind for me
- water changes, water changes, water changes - start at keeping nitrates below 20 ppm
 
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duanes

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I agree about the nitrates being much too high and are a source of chronic infection.
You need to increase water change frequency too bring them down to below 10 ppm or below (my personal goal for my tanks is below 5ppm)
The especially long lived and large species are often chronically diseased when nitrates are elevated.
Water changes could easily be accomplished by diverting the flow from the filter that normally goes back to the tank, , to the outside on the lawn or garden (or anywhere else for that matter.
I had over 20 tanks in Wis, and with the turn of a valve, old water was diverted to the garden, so I could do hundreds of gallons in minutes.
When I lived there I had a permanent PVC line to the garden, because i tried to do 30-40% water changes every other day
1670493825732.png
I also wonder, if you are feeding too much protein, Pacu are omnivores but turn primarily vegetarian as adults, eating seeds and fruit.
In fact they are some of the primary dispersers of fruit tree seeds along the rivers in S America.
A friend, who is a curator of fishes at a public zoo, has 3 Pacu, similar in size to yours, in a 10,000 gal tank and feeds everything from bananas to cukes.
 

phreeflow

Goliath Tigerfish
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Perhaps you’re feeding too much too often. Fish that size don’t need to eat multiple times a day or even every day. I’d consider reducing feeding to once every other day or less and increase water changes until the water quality improves.

Also, Pimafix and Melafix may work but I prefer Seachem Kanaplex if I must dose medication. It does a good job at treating bacterial infections in an emergency but use meds as a last resort.

Better yet, you can add some non-iodized salt to help reduce nitrite toxicity and improve osmoregulation by lowering osmostic stress. It also improves gill function and depending on how much you add, it can prevent or fight off certain pathogens like bacteria, parasites, and such
 

Steven's Pacu

Exodon
MFK Member
Sep 27, 2019
21
27
21
58
Fair Haven VT
Screen shots of the videos I took, for faster reference? Not wonderful at anything technical. More coming so I don't overload system.
 

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