Dead Guppies

[samanthaalice]

So...
I have a 100L tank with 2 mollies, 3 platties, 1 small catfish, 20 or so guppy and molly fry in a net breeder, and until today 7 guppies. All the guppies are dead or dying except for a brand new one I got on saturday! PH is too high but don't have any PH down left.
The other fish are all completely fine but the guppies are not ok. I removed 3 dead fish and whilst doing that i noticed lots of clear mucus built up around the suction caps on the net breeder so i cleaned it off.
I have separated the other 3 sick guppies really just for the simple reason that if they die they are easier to remove.
Could it be the PH level killing them? No signs of ich or fin rot.
I am worried that the babies will get sick and start dying too which would be awful.
This has been an awful two weeks for these fish- just got rid of a BETA which killed 3 mollies and a platty including my massive black male molly which I was very attached to!

 

[Essjay]

First of all, the livebearers you have all prefer a high pH, so don't try to lower it. If you have been using a chemical to alter the pH, the swings in pH that are the likely result are bad for the fish.
The stuff on the suckers is common, just wipe it away.

How long has the tank been running, and how did you cycle the tank? Guppies are notoriously weak fish, and if you are doing a fish-in cycle, they would likely not survive the process. What are your readings for ammonia and nitrite?
If the tank was fishless cycled, and has been running quite a while - did you get the guppies from the same shop? If you did, it could be they had weak stock. Either replace them with fish from a different shop - or preferably a local breeder - or don't have guppies. With all those livebearers in your tank, you'll soon be overrun with fry, so buying a different type of fish to replace the guppies might be a better idea.


Finally, you say your betta killed some fish. Some bettas are extremely aggressive, and they should be kept alone in their own tank. Other bettas are more laid back, and can be kept with other fish, only you don't know what a particular fish is like till after you buy him. Did you actually see the betta kill the fish? Could they have died of some other cause?

 

[samanthaalice]

I did a fishless cycle and tank has been going for 3 months or so. My sister came home and told me that the PH was fine so I know now it isn't the problem. The guppies were from 3 different stores.
The betta we had was most definitely attacking the others...he attacked the three mollies leaving them with barely any fins or tail and they died a day or so later. We started putting him in a net breeder at night and the attacks stopped, so 100% sure it was him.

The three guppies I have quarantined seem ok for the moment, I will see what happens in the morning.
Amonia and nitrite levels all fine.

 

[samanthaalice]

UPDATE
Only the new guppie made it through the night. Found one guppy fri dead and a couple of others are sluggish and have closed tail/fins.
Have added some aquarium salt today.

 

[samanthaalice]

More dead fry...this is horrible! The molly fry are fine though which is something i guess

 

[samanthaalice]

More dead fry...this is horrible! The molly fry are fine though which is something i guess