I totally overcrowded my tank and its worked out fine so far. How long do you think it will last?

Question

For 2 1/2 years I've sucessfully kept these fish in a 90 gallon tank

Fire eel 13''

Jack Dempsey 8''

Convict 5''

Firemouth 6''

Severum 8''

"Rainbow" Eartheater 6''

Red Tailed Shark 5''

Gold Nugget Pleco 6''

9 Tiger barbs 2.5-3''

Rainbow Cichlid 6''

Blue Acara 7''

Clown loach 10'' (schools with barbs)

I've used these filters along with a 10 gallon water change daily

FilStar xP4 external Canister Filter (up to 265 gallons)

Hagen Fluval FX5 High Performance Canister Filter (up to 400 gallons)

Eheim Professional 3 external canister filter (up to 300 gallons)

The fish seem to be doing great, all are getting enough food and are colored beautifully. Aggession in the tank is very low, mostly because my jack is a poof. If its lasted this long, do you think it will stay that way?

Answer 1

Your tank is heavily stocked, but not by any crazy amount.

The tank has enough space to allow territories and fish to get out of each others way, so the agression is not bad.

You have 3 times the filtering thats recommended, so the filters are able to process the waste.

You are changing the water regularly, more than most people, so you are controlling Nitrate buildup.

The 3 filters will be circulating the water well and providing plenty of oxygen.

So no reason it wont continue to work, as long as you keep up the maintenance. None of the fish will grow into tankbusters like Pacu or Red Tail Catfish would.

Yes you are pushing the limits, but not breaking them.

Ian

Answer 2

I don't completly agree with my friend Ian, but mostly I would.  I'd have to say yes, you have outstanding filtration going.  I also think you're doing pretty good on water changes, though you could move to a larger change less often, it's up to you on that.  Where I don't agree is the tank size with your stock.

I do understand things are ok now.  I've never liked the idea of keeping any rule the tank types along the same lines with Africans, where you overstock.  South Americans don't behave nor carry the same aggression types like Africans.  At some point in the future, what I strongly feel is going to happen, is that Jack Dempsey is going to figure out he's a Jack Dempsey and exert himself in there.  Now let's look at this.

Blue Acara, very beautiful fish, I like these, even had them in the past.  Will attain a decent size, but very peaceful and mild too.  An almost full grown Convict, male or female?  Convicts when breeding are downright nasty fish, and would fight back against the Dempsey, but being a solo Convict, is at a slight disadvantage.  This fish has some decent bulk too.

Not sure about the Rainbow Cichlid, but if you happen to have the scientific name, it would help  Already at a decent size there too.  Then you have two more medium level aggressive, almost full growns in the Severum and Firemouth.  That is ALOT of inches in that stock.  Even with a 90, that does not leave much space for the others to take cover from that Dempsey when he starts acting his true nature.  

I'm fairly surprised you've pulled this off so far.   How much longer it will take could literally be as soon as tomorrow, maybe even into next year.  Very hard to predict.  What I do think though, is your Acara will be the first to go, then your Severum, then firemouth.  I can't say about the Rainbow because I really don't know what that is.  I do feel at some point in time, Jack is going to take care of business.

I don't see your pleco or loaches as being targeted.  Generally bottom feeders are ignored because they wouldn't appear to be challenging the Dempsey.  It WILL see the others as a challenge at some point.  The convict I think would end up being the last to go.

If it were me, I'd begin replacing the Acara, Convict and Rainbow, and try to keep maybe the Firemouth and Severum.  I think it's just too many other targets for a tank that size.  Maybe if this were like a 150 or 180, it might offer just enough space to allow those bulkier other South Americans enough space to hide.  What I think you're going to end up having is one of those old musical chairs happen.  Someone is going to not have a place to go when Jack starts drinking due to the size of all those, and get left out to face the music.  When that one is gone, then Jack will go after the next one on his next binge and so forth.  That's just my thoughts.  Doesn't mean it will happen, I'm not God lol.

Answer 3

You answered your own question.  You can put as many fish into a tank as can be.  Overcrowding only comes into play when the ammonia produced by the fish outpaces the biofilter's capacity to process it.  By changing the water daily, you are keeping the by products of so many fish to a minimum.  It will stay that way as long as you keep changing 1/9th of the water/day.