White slimy substance in tank

Question
QUESTION: I have a 45 gallon tank with 4 Angelfish,10 neons,1 chinese catfish and a small pleco they have been doing very well together and still seem to be doing well but I noticed this white slime on one of the plants  when i was doing a water change, only one of the angels seems to be acting differently hovering at the bottom by the plant with this white stuff on it, the slime looks like it has little bubbles in it..  should I be concerned about this?
ANSWER: Dear Lindsay,
The most frequent cause of slimy patches in your aquarium is usually due to leftover food settling in that area. It then becomes covered by a fungus that creates a sometimes almost fuzzy patch. It's easy to remove and siphon out. The easiest way to prevent this is to try to avoid letting food drop to the bottom of the tank and feed less. With your bottom feeding catfish and pleco try to avoid their food getting underneath ornaments or trapped in between plants or decorations. One good way to feeding bottom dwelling catfish is to have a cave (you probably already have one or two) for them to stay in and place their sinking food inside the cave at night so they can easily find it and clean it up. You could also add some 'scavenging' catfish like the cute Corydoras catfish that are very helpful in cleaning up leftover food at the bottom (but they must also be fed special sinking food).

But usually the appearance of some white slime isn't a great cause of alarm and is often just a one-time occurance so drastic measures aren't usually needed to prevent it. Just try feeding more carefully and it shouldn't re-occur.

I really hope this helps!
Happy fishkeeping!
Karen~

---------- FOLLOW-UP ----------

QUESTION: Hi Karen, thanks for the good advice on that although, shortly after the white slime appeared(but after i cleaned it up) one of my angelfish just died for no apparent cause? the others seem fine  and the white slime hasnt re-occurred. I heard from someone that a 45 gallon is too fish for angels but others say it is a good size? thanks in advance
**Lindsay**

Answer
Dear Lindsay,
Sorry to hear about your Angelfish!
If the Angels were a recent addition, it may have just that particular angelfish was weak or sickly and may not have even shown symptoms. Angelfish frequently are sickly in petstores. But we also need to make sure there wasn't a water quality issue here. Like ammonia or nitrite.
Normally a well-established and cycled tank will not have any measurable ammonia or nitrites due to the biofilter, which is your 'good' bacteria that live in the gravel bed and in all surfaces of the tank.
If the tank has been recently setup, it may not have cycled or established if of these 'good' bacteria which takes many weeks. During that time ammonia can build up very fast and it is very dangerous for fish.

You can easily test your water for ammonia and nitrites from a store-bought test kit. If your tank happens to have ammonia. It's likely still cycling or if it's already been cycled. There may have been something that overloaded the biofilter bacteria like an accidental overfeeding or maybe a hidden fish that had passed on without you knowing and it hidden behide a rock. Or if the gravel or filter was cleaned too thoroughly it could have destroyed the good bacteria off these surfaces.

The best solution of you have ammonia problems is to do water changes of 50% or more, everyday if you have to for the sake of your fish's welfare.

Its good to hear your other fish are doing good and I hope this continues. I'm also glad the white slime has re-appeared, it very likely was just some leftover food that settled out of reach of your fish.

On the 45gal for Angels question. A minimum tank size for Angelfish is 29gallons. However your 45 gallon is perfect for Angels.

I really hope this helps as always!
Happy fishkeeping!
Karen~