40 gallon / 155liters - silent cycle - green or red? Stocking suggestions please!

[Cmdr_DASh]

One of the fishes that was caught in the filter inlet is doing better, I've seen it swimming around. It's one of the largest of the group.

Both of them are recovering, eating and swimming around. Amazing.

 

[Cmdr_DASh]

I'm slowly reducing the temperature, I'm at 28 today.

Unfortunately I think something is going on with the fishes... they are staying mostly hidden and coming out to eat. I have watched them closely when feeding this evening and it looks like a secondary fungal problem is showing up... I thought initially it's the 2 fishes that got stuck in the inlet of the filter but now I think I've seen it on 2 more fishes besides the 2 that were injured and have some missing scales.

I tried to take a picture but it didn't work out. They are mostly staying in the back of the aquarium, in between the plants. The few that play around are looking fine. I will try to take a picture when feeding in the morning. And 1 fish has a strange stomach shape, like he ate something hard, I was thinking it's from eating, but I've seen it before on it so it maybe is permanent...

 

[Cmdr_DASh]

they are staying mostly hidden

Maybe just scared of me? I've put a web camera next to the aquarium and I can see them swimming around... but if I show up, they hide...

 

[Animallover😍]

Maybe just scared of me? I've put a web camera next to the aquarium and I can see them swimming around... but if I show up, they hide...

My rummy nose used to be like that. They got used to me and now they stop playing about with the current made by the HOB and when I come they crowd to the front instead. I hand feed them.

 

[Cmdr_DASh]

Very sad update, I found one cardinal tetra dead, floating in the plants. It wasn't dead this morning when I fed them, so I found it pretty quick. I have no idea what the problem is or what to do.

Water parameters:

Date	t (oC)	KH (odKH)	GH (odGH)	CO2	pH	NH4 (mg/l)	NO2 (mg/l)	NO3 (mg/l)
19.11.2021	26	7	7	22	7.7	0	0	0

It was discolored and seemed bent upwards...

 

[Naughts]

It was discolored and seemed bent upwards...

and it has a swollen stomach.
It may be an egg bound female. Do you de-worm all your fish?

 

[Naughts]

26

The water should be warmer for cardinals.

 

[Cmdr_DASh]

and it has a swollen stomach.
It may be an egg bound female. Do you de-worm all your fish?

About half of them have bigger bellies, I thought females. Gosh, no, I did not de-worm. These are my only fish. I'll read on de-worming...

The water should be warmer for cardinals.

I thought they are fine from 22 to 28. My plan to was to have the temp at 25 but now, after one died, I'm not planning on changing anything until I see what happens next... I don't know what the problem is, but I know that temperature drop could be an issue... I did go from 30 to 26, about 1 degree per day.

 

[Cmdr_DASh]

My fish have been doing better and better the last few days... Today they have been much less shy and more active (as opposed to hiding in the back)

https://imgur.com/a/VGRerbC

 

[Cmdr_DASh]

Higher temperature, going from 24 to 30, and running air full time, more O2 in water (as opposed to only 2 hours before). I think this is the reason, but I may be wrong. PH has been stable before this.

My pH is staying at around 7.8 maybe 7.9 even after lowering the temperature (I'm at 25 now) and reducing the time the air pump is on (about 5 hours now, from full time during high temperature). My fish seem fine but I don't think they are thriving...
Should I look at using pH lowering products? My KH is at 7.

Thanks in advance for your advice!

 

[Cmdr_DASh]

I can see in another thread that adding chemicals to lower pH is not a good idea and I was expecting it...

 

[Colin_T]

There's too much water movement in the tank for tetras. You can see them being pushed down by the current when they swim through the middle.

Adjust the filter outlet so there is less water movement.

 

[Cmdr_DASh]

There's too much water movement in the tank for tetras. You can see them being pushed down by the current when they swim through the middle.

Adjust the filter outlet so there is less water movement.

Thanks a lot @Colin_T , I'll give it a try. I'm struggling a bit with the filter flow - in the last video it was strong after filter tubes clean up (they were quite dirty before), now it's a bit more slow again, not entirely sure why, but I'll adjust outlet flow direction.

 

[Byron]

My pH is staying at around 7.8 maybe 7.9 even after lowering the temperature (I'm at 25 now) and reducing the time the air pump is on (about 5 hours now, from full time during high temperature). My fish seem fine but I don't think they are thriving...
Should I look at using pH lowering products? My KH is at 7.

Thanks in advance for your advice!

As is explained several times in the linked thread, the pH is connected to the GH and KH. Never attempt adjusting the pH without dealing with the GH/KH. KH here is 7, presumably 7 dKH (?), what is the GH?

 

[Cmdr_DASh]

As is explained several times in the linked thread, the pH is connected to the GH and KH. Never attempt adjusting the pH without dealing with the GH/KH. KH here is 7, presumably 7 dKH (?), what is the GH?

KH is 7 dKH and GH is 7 dGH. These 2 have not changed at all throughout November.