I've been keeping 4 parrot fishes in my mom's 15gal tank,how can i keep this up?

Question

This was the first time i had fish and didnt cycle the tank.
The fish had black spots and white scratches all over.
I thought they were dead,because they were all lying in the bottom.
I asked how can i keep the fish alive and one answered my question and told me to add more methylene blue and my fish got better.(whoever you are,thanks)

2 months after i added a fish i caught fishing in a river in bataan (which is in the philippines,i am from the philippines btw) which is called by the natives "biya" which is a bottom dweller and does not swim a lot.it is about 3 in.

I've think i did a good job in this tank as i never had problems since the first month.
I feed them twice a day.
there are currently 3 red parrot fish,1 yellow parrot fish and 1 "biya".
i clean the whole tank every month.
-removing everything and rinsing it with waterr,adding methylene blue and 2 other liquid which i forgot the name.

tell me advices in keeping the tank,btw...am i having a good job?

do you know what "biya" is?
i kept the tank since early january.

they all look good.
I feed them pellets,and in rare occasions, shrimps caught in the river in bataan.
(people are allowed to fish and take it home.)
im from manila btw.

Answer 1

A fifteen gallon isnt even big enough for one parrot fish. Please, please please get a larger tank, or smaller fish. It's hard to not be harsh with you, when you keep asking the same or similar questions, and not listening to the answers. Both the tanks you have are overstocked, most especially the parrot tank. I have seen parrot fish as big as my hand. They get HUGE.

Answer 2

A 15 gallon is too small for those fish, so no matter what you do or how well you care for them, it will only be so long before you run into problems with them.

Tanks should be maintained on a regular basis and never be cleaned out completely. The substrate should be vacuumed, the filter cleaned of waste, but not bacteria, and the water changed in portions. Once per week is ideal, and once every two weeks is ok too, for this.

You should not be adding medications and additives for no reason - only if there is a problem with the tank. The only thing you should be adding to the tank after each water change is de-chlorinator.

Answer 3

i agree with ghapy, your tank is too small for your parrots in the long term. they grow quite large. they will need a 75 gallon tank minimum i think for the 4 of them.

as for cleaning, a 20% water change and gravel vac once a week is the regular for most fishkeepers, this way you don't overclean and put the tank back into a cycle, and it doesn't shock the fish either.

i would be doing tests on your water for ammonia/nitrate/nitrite though as it is overstocked.

i do not know what a biya is, do you have a latin name for it?

Answer 4

dont take the tank apart every month just clean the gravel
thats whats making them sick