Tank sickness or other - help!!

I woke up this morning and fed my fish to find sunny one of my newer angels floating on the top, one eye seemed to be pushed in/missing and tail had parts missing. I’m questioning this as recently (4 weeks or so ago) lost another angel Batman. Both Batman and Sunny purchased at different times from different places but both seemed to not grow like the others I have bought, my biggest angel Dart is about 3 or 4 times the size of Batman and Sunny.

Anyway, I just want to know if there is bullying happening, or if this might be something more serious.

In my 100L tank I have 8 x bristlenoses, 2 x corys, 1 x ghost knife, 1 x red tail shark, 2 x opaline gourami, 2 x Cory catfish, and 4 x angles left now

Never seen any bullying between any fish, except I do notice the red tail shark keeps the male gourami in check! But the shark doesn’t care about the angels or any other tank mates. I know the male gourami likes to chase the female gourami, but they aren’t too bad considering the species and the female shows no sign of stress or fin damage/nip etc.

So is it possible the angels are ganging up on the smaller ones, and I am not seeing it?? What’s a good number of angels to have? It’s hard to sex angels but I believe I have 1 of each sex, and then unsure of the other two as still too small, but they have sort of paired up and Sunny and Batman were always sort of on their own…

Pls help sorry for long post.

Ps.
Water is 6.8ph (trying to get up to about 7) 0 ammonia 0 nitrite and 5.0 nitrate
Tank is 100L
In QLD so no heater as water is naturally pretty warm, but have filter light and also air pump.
Diet consists of peas, blood worms, flakes

Pic attached of tank, remainder angels and poor Sunny

I would say the tank is too small for that many angelfish once they have matured. You probably have a pr and the older angelfish are killing the new angelfish.

The tank size could also be an issue when the gouramis become sexually mature, assuming they aren't already.

You mention having 8 bristlenose catfish. That's a lot for one tank. If they are young and you are growing them up to breed, that is fine but they will need more room and food when mature.

Someone is chewing holes in the plants and that could be the redtail shark or the bristlenose, or both. The loaches might chew on the plants too.

If you increase the lighting period to 16 hours a day, it will help encourage algae to grow on the glass. The fish can then eat that instead of the plants. If you find too much algae grows, then reduce the lighting period by an hour and monitor over two weeks. If there is still too much, reduce it another hour and monitor. Continue doing this until you get some algae growth for the catfish but not so much that the tank is covered and you can't see into it.

You should have some real driftwood in the tank for the algae eaters to graze on.

Your tank looks a little cloudy (milky colour) and this is usually caused by uneaten food rotting in the tank, or a filter that is not fully established. Check the ammonia and nitrite levels and do a 75% water change and gravel clean the substrate every day for a week.

Colin_T said:

I would say the tank is too small for that many angelfish once they have matured. You probably have a pr and the older angelfish are killing the new angelfish.

The tank size could also be an issue when the gouramis become sexually mature, assuming they aren't already.

You mention having 8 bristlenose catfish. That's a lot for one tank. If they are young and you are growing them up to breed, that is fine but they will need more room and food when mature.

Someone is chewing holes in the plants and that could be the redtail shark or the bristlenose, or both. The loaches might chew on the plants too.

If you increase the lighting period to 16 hours a day, it will help encourage algae to grow on the glass. The fish can then eat that instead of the plants. If you find too much algae grows, then reduce the lighting period by an hour and monitor over two weeks. If there is still too much, reduce it another hour and monitor. Continue doing this until you get some algae growth for the catfish but not so much that the tank is covered and you can't see into it.

You should have some real driftwood in the tank for the algae eaters to graze on.

Your tank looks a little cloudy (milky colour) and this is usually caused by uneaten food rotting in the tank, or a filter that is not fully established. Check the ammonia and nitrite levels and do a 75% water change and gravel clean the substrate every day for a week.

Click to expand...

Thank you, such a great response.

I’m saddened that we have too many fish, I asked my local pet shops and aquariums they all told me it was fine

All the fish are juveniles at this stage, planning to upgrade to a much larger tank in future, (but keep this one too) We already have another tank as well which is more for our schooling fish.

Yes forgot to mention I have 1 x loach, she loves to suck the plants, I actually watch her do this and we go through plants like crazy!! I will definitely try this tip for lighting! I never realised that would stop her doing it.

With the driftwood, only reason I don’t have any in there is because we used too in our other tank and i believe it was actually effecting the PH. But I have different fish in this tank so maybe it won’t??

not sure if the water may look cloudy because of me just feeding them or because Photo quality not good. Doesn’t look milky in person. I test the water regularly because in the past had major issues with ammonia - water tested yesterday and the only thing that I wasn’t happy with was PH. This tank seems to range between 6.6-6.8ph generally but I’d prefer 7ph. Also doing gravel clean today as it is due now.

Thanks for your great response again, and if you have any further tips or advice after seeing the above please let me know

The minimum size tank you want for a group of angelfish is 4 foot long. Bigger is better.

Loaches do best in groups of 6 or more so when you get a bigger tank, maybe get it some friends. But watch it in case it has gone nuts and tries to kill the new ones.

I don't normally recommend loaches and catfish in the same tank. Generally it's best to have either loaches or Corydoras, but not both unless the tank is really big (6ft plus).

Most fish prefer algae over plants because the algae is easier to eat and digest. Having algae on the glass might not stop the loach eating the plants but it will give the loach, shark and bristlenose an alternative food source and the plants might not get eaten as much.

You could grow aquarium plants outside in plastic tubs or ponds and bring the plants in for the fish. You can do the same thing with smooth rocks and leave them outside in a pond or tub of water. When they get covered in algae, you put the rock in the aquarium and let the fish graze on it. When the rock is clean, swap it for one outside in the tub.

Some driftwood can lower the pH but most doesn't. You don't need a huge piece for the tank, just something big enough for the shark and catfish to graze on.