Bettas keep dying and sudden algae growth
So i have two aquariums one is devided with 3 betta males and one with female bettas and some other fish. I take the exact same care for both of them and both of them have the same amount of sunlight. The one with more fish is bigger tho.
The one with three male bettas has a filter inisde the aquarium but a quite powerful one.
The one with more with has one outside.
Both have the same heaters and lights
The smaller one has more plants tho and that is because the bigger one i had a carpet and aome plants and one day all plants died just lile that thats problem no.1
Why did all my plants in that aquarium die? The ones in the othwr one are perfectly fine i use the same additives and thw same water.
On the bigger one every now and then theres an extreeme amout of algae growth like i could be cleaning it today ans tomorrow it would be green.
Thata problem no.2 which i also do not understand.
None of them have direct sunlight and are next to eachother. In the other in i have almost no algae growth.
In the bigger aquarium betta fish keep dying and idk why there are no signs except the day before they lie on the ground and breathe heavily. No other signs of anything. But there is oen betta that doesnt die and i havw her since the setup and othwr fish are fine too. The other tank bettas are fine. Not one has died in a year now.
And i do the exact samw in both tanks.
Please help 😞