Stocking Numbers

[Just_Keep_Swimming]

I know this has probably been asked a million times on these forums so I apologise first off for something that I'm sure has been covered to death on here but just trying to gauge how well I'm stocked in terms of number of fish in the tank. I've heard the basic rule of one inch per gallon rule isnt great so just trying to get advice/opinion if I would be safe putting more or in or should I stay where I'm at. I have no concerns with water parameters at present. Picture attached to give better idea of current stock etc (just about to do my weekly tidy maintenance tonight FYI).

Setup (Feb21)
Low tech - 110l tank
External filter - (Oase 350) - arriving tomorrow

Current Stock
7 Tiger Barbs
2 Female Betta
5 Cardinal Tetras
3 Oto Cats
1 Bristlenose Pleco

Maintenance
50%+ water change per week

 

[PheonixKingZ]

Have you noticed any aggression between the female Bettas and the Barbs? That is what would concern me the most. Barbs are notorious fin nippers.

Do you know your water hardness?

 

[cdelly]

It's not the litreage it's work out from but the surface area, so you could have a tank that is 10foot deep by 10 inch by 10 inch. Lots of water but not a big surface area for gas exchange(oxygen in co2 out etc) so in that tank you would have to use a big filter and air pump for maybe 5 inch of fish.

If you search for tank calculators, they out there that will give you an idea of amount of fish you can have ??

 

[Just_Keep_Swimming]

Have you noticed any aggression between the female Bettas and the Barbs? That is what would concern me the most. Barbs are notorious fin nippers.

Do you know your water hardness?

Barbs and the bettas get along together really well and I literally never see the barbs annoying the bettas or vice versa. I cant remember the water hardness off the top of my head and not at home just now, it was on the low end of the scale.

Is water hardness one I should be particular concerned about? I'd been more concerned with ammonia, ph and nitrates etc

 

[PheonixKingZ]

If you search for tank calculators, they out there that will give you an idea of amount of fish you can have ??

Stocking calculators usually aren’t accurate and shouldn’t be used for solid information.

 

[PheonixKingZ]

Barbs and the bettas get along together really well and I literally never see the barbs annoying the bettas or vice versa. I cant remember the water hardness off the top of my head and not at home just now, it was on the low end of the scale.

Is water hardness one I should be particular concerned about? I'd been more concerned with ammonia, ph and nitrates etc

Water hardness is important. If you keep hard water fish (livebearers) in soft water (tetras are probably the most common soft water fish) and vise versa, issues can occur. These issues include genetics (after breeding), kidney damage, and blockage in the organs.

Other water parameters definitely take precedence over water hardness. But water hardness is still important and could lead to the issues I mentioned above, if not kept in check. Ammonia should be 0ppm if it is a cycled tank. Fish can die from ammonia poisoning, so this is important. Nitrate should be 0ppm-20ppm, the less the better.

pH is a reading that tells you how acidic your water is. For the fish in the tank now, the pH should be at 7.0-7.6. (The normal level for tropical fish)

 

[cdelly]

Stocking calculators usually aren’t accurate and shouldn’t be used for solid information.

that's why i said "an Idea"

 

[PheonixKingZ]

that's why i said "an Idea"

Usually people take that “idea” as literal, and they way overstock their tanks. That’s why they are generally not recommended.

 

[OliveFish05]

Hi! I have heard that otos do much better in groups of 6, which is not possible in your tank size. I would be very cautious with only 2 female bettas, it is recommended that for a female betta sorority you have 5 at least. I kept two female bettas, and while they did not fight they did stress eachother out terribly.

 

[cdelly]

the thing with stocking levels, is they don't take filtration into account, some ppl have loads of fish but have massive filters that can handle the waste.

with malawi they recommend to overstock the tank to try and cut down on aggression, but you need filtration to match as well.

now i not saying whack on a massive filter and you can unfree willy and stick back in a 5 foot tank either

 

[Just_Keep_Swimming]

Hi! I have heard that otos do much better in groups of 6, which is not possible in your tank size. I would be very cautious with only 2 female bettas, it is recommended that for a female betta sorority you have 5 at least. I kept two female bettas, and while they did not fight they did stress eachother out terribly.

Hi thanks for the reply. Why do say 6 oto's is not possible in my tank? Just because I'm already close to the max stock?

My two females dont really seem to interact at all. How did you know they were stressed? Lost colour?

 

[Just_Keep_Swimming]

the thing with stocking levels, is they don't take filtration into account, some ppl have loads of fish but have massive filters that can handle the waste.

with malawi they recommend to overstock the tank to try and cut down on aggression, but you need filtration to match as well.

now i not saying whack on a massive filter and you can unfree willy and stick back in a 5 foot tank either

The oase 350 says its for tanks up to 350l and 1100lph so I'll have a 10 times turnover rate. Does that count as massive? Lol

 

[PheonixKingZ]

Hi thanks for the reply. Why do say 6 oto's is not possible in my tank? Just because I'm already close to the max stock?

My two females dont really seem to interact at all. How did you know they were stressed? Lost colour?

You are pretty close to your stocking limit.

If I were you, I would get 3 more oto’s, but move the 2 females to another tank. That would clear up room. After that, don’t add any more fish.

 

[OliveFish05]

Hi thanks for the reply. Why do say 6 oto's is not possible in my tank? Just because I'm already close to the max stock?

My two females dont really seem to interact at all. How did you know they were stressed? Lost colour?

Yes basically what PheonixKingZ said. With your current stock it would just be a lot for your tank size.

I knew the female bettas were stressed by watching their behavior. They didn't eat as much, they hid all the time, and they just looked unhappy in a way

 

[cdelly]

The oase 350 says its for tanks up to 350l and 1100lph so I'll have a 10 times turnover rate. Does that count as massive? Lol

Magical words them "UP TO" 4l liters and hour is still upto 350l, like the ISP that says with speeds UPTO 500 Mb and you get nowhere near that.

with filters you have to take into account the head(height the water has to be lifted into the tank) length of piping, the filters will gunk up an restrict flow.