I have a problem... I cannot keep pleco fish alive for some reason. They keep dying and i dont know why? first thing, ive had my water tested and everything is great they say at the fish store. My tank is cycled. I have 3 angel fish and a leporinus shark in the tank who are pretty aggressive. I like to keep the pleco's because they help keep my glass of my 50 gallon tank clean. I have just bought a new one last night and now it is missing an eye. I was cloudy and now its gone and it looks bloody. I do water changes about once a month, well i wouldn't say im changing out the water mainly just replacing from water evaporation. Usually about 25% and this is usually when i lose them. I use algaefix, stability, and stress zyme when replacing the water. I recently started adding in cucumber and lettuce fot them to feed on. This still did not save them, now im afraid this one now since it doesnt have an eye im afraid he wont last long and will probably die too. Can some one please help me??? Or is there another fish or snail that would work better for keeping the glass clean?
he is probably being attacked by your other fish if he is randomly missing an eye?
First, never buy a fish from a display tank that contains any sick fish. When you get the healthy fish home, try drip acclimation:
This procedure greatly reduces the stress a fish experiences from getting netted and moved to a different aquarium. When fish are stressed, the usual result is a weakened immune system then illness.
When the pet shop tests aquarium water, they usually say it's fine or you need to add something. To be sure of water quality, a test should provide actual numbers. For example, ammonia and nitrite must always be zero, and nitrate should measure below 40 ppm. Temperature and pH should be species appropriate. Many aquarists own and use a water test kit; water tests at the pet shop can be used as a backup or comparison.
To keep the aquarium healthy, you should be changing 20 or 25 percent of the water every week and feeding no more than the fish eat in a couple of minutes. Feed the pleco after lights out, and remove any uneaten veggies in the morning. Partial water changes can be less frequent if the aquarium is not carrying a large biological load, but once a week is a good starting point.
Adjust the temperature of the replacement water to about that of the aquarium, and treat it with a good tap water conditioner like Stress Coat Plus. Things like Stress Zyme are intended primarily for starting bacteria colonies associated with the nitrogen cycle. Algae killers may kill other things that you don't want killed. It's much safer to control algae by operating the light about ten hours a day and using the feeding schedule mentioned above. Fast growing plants like hornwort will also help.
Still on the subject of algae, plecos and snails are not nearly as thorough as most aquarists, and every living critter adds to the biological load on the aquarium. In addition, plecos are nocturnal and have been known to suck the protective slime coat off sleeping tankmates.
Finally, the aquarium needs a tight fitting hood to prevent evaporation. Some of the minerals in aquarium water do not evaporate and thus become more and more concentrated as water evaporates.