What do you guys consider as an acceptable nitrate range for big cichlids?

[RD.]

IME territorial size requirements diminish rapidly when a single specimen is kept. Hence a single O, or a single RD, or a single Mayan. Nobody here keeps tanks that replicate nature, most not even remotely close, including myself.
A 100+ gallons dedicated to a single 12" ish fish is more than most fish in this hobby end up with, and is more than adequate for a long healthy life. What the OP needs to figure out is whether he wants to keep a single large wet pet type fish, or a community of smaller, more managable fish.

 

[Gourami Swami]

I generally aim to keep my nitrates under 20ppm. They are usually closer to 10-15 before water change on WC day.
What are your nitrates after a week? Right before the WC? (or after half a week, if you're doing 2 a week)

Honestly I do think your reduced list will still be too many fish as well. Especially since you've got some quite aggressive species like the mayan. I think you will have lots of trouble with aggression and with nitrates as they grow. I'd look to sell off more and keep the less nasty species, or get another large tank to split them into. The problems will probably start arising within 6 months or so as the fish grow

 

[Toiletcar]

IMO-would stay away from a large cichlid community in something like 125-150g. Small to medium if doing a community or single or pair. Even a 150g is too small for the largest like dovii, umber, pbass etc.

 

[Kvandy]

If aggression doesn’t become a problem you see tanks like this work all the time if you are willing to put in the work. I use to keep Cichlid community tanks with rd,Texas, flowerhorn,gt, etc. all mixed together and now I keep species only tanks with either a single fish or a pair and I enjoy it a lot more. Better behavior , the fish have more room, less stress, cleaner water, your not constantly moving fish and the decoration around. Less is more.

 

[RD.]

Cichlid community tanks can work, but a 125 isn't a tank I would recommend attempting to try it. The tank is simply too damn small for any kind of real long term success.

 

[SwampFins]

Thank you for all the input everyone, it is much appreciated!

I do agree I might need to look into reducing my stock a little further in the future but for now I've rehomed a lot of the fish and managed to get the nitrates back to 10ppm.

As of right now I kept:

1 Oscar
1 Red devil
1 Mayan
2 Bichirs
3 Nicaraguans

In the next following weeks I will be setting up a pond in the backyard to grow some plants and what not and I'm thinking I might move the oscar outside as I've been having some issues with him trying to jump when feeding and banging then glass a little too hard for his own good.

I think this will help clear some space in the tank as well as providing them with even more space long term.

 

[Gourami Swami]

If your having issues with the Oscar jumping already, I'd make sure the pond has a steep bank that he can't jump out of, or is covered with a net. Don't want him jumping out of that either!

The fish you kept, are not a mix that most of us would recommend, and I think you will see that you still will have aggression issues. But, we all learn through experience, so good luck, and keep a divider on hand!

 

[LBDave]

I generally aim to keep my nitrates under 20ppm. They are usually closer to 10-15 before water change on WC day.
What are your nitrates after a week? Right before the WC? (or after half a week, if you're doing 2 a week)

Honestly I do think your reduced list will still be too many fish as well. Especially since you've got some quite aggressive species like the mayan. I think you will have lots of trouble with aggression and with nitrates as they grow. I'd look to sell off more and keep the less nasty species, or get another large tank to split them into. The problems will probably start arising within 6 months or so as the fish grow

I agree with this. I tend to pack the fish in because I don't have room for huge tanks. It's doable if you pick the right fish. It's also a little risky and difficult to grow the fish at the same rate to prevent aggression. Expect do do lots of tank cleaning and water changes. Plants will help with the nitrates but will not cure it.
RD's approach is more full proof but tank can look a little bare.

 

[dan518]

Nitrate aren't the be all and end all, there's many other nasties that build up in a closed system, but they are a good indicator for a water change schedule. A 10 ppm rise above your tap water is ideal but 20 ppm isn't too bad.
I personally feel with large cichlids 40 gal per 1 lbs of fish is the absolute max stocking, anything over this and the fish will never reach its full potential.
A few full grown weights which I know
Oscar 14 inch 3 lbs
Oscar 6 inch 0.25
Labiatus 13 inch 2 lbs
Trimac 14 inch 3 lbs
Jag 16 inch 3 lbs
Jag 12 inch 1 lbs
Umbee 20 inch 4.5 lbs
Dovi 28 inch 13 lbs

 

[tiger15]

Nitrate isn’t the problem, but a proxy indicator of other unknown and untested pollutants. Chief among them are heavy metals and complex organic compounds that will accumulate Indefinitely without WC. Planted tank folks routinely dose nitrate to as high as 100 ppm with no ill effect on fish, but if that level is generated from fish waste, the water is very polluted and the fish will be sicky. It doesn’t matter much what nitrate level it is, as long as you do massive WC weekly to get rid of the pollutants, the fish will be healthy even in crowded conditions

The above weight correlation is interesting, indicating weight and size is not linear, but increases geometrically. So it’s easy to grossly underestimate how much more pollution your growing fish are generating.