How long has your tank been set up? It's normal to have outbreaks of various
kinds of algae in a new tank, as it finds its balance.
Any suggestions. Right now it actually looks kinda neat but I think a couple
of weeks growth like it has been and all will be lost. Chemical solution?
Maybe a fish I need to add, seems I remember seeing that one particular fish
loves bearded algae but I can not find that post? Snails?
People get Siamese Algae Eaters (SAEs) to take care of BBA. However, your tank
is a little small for them, since they get to be almost 6", do best in groups,
and are very active. Your calm, quiet gouramis may not appreciate SAEs as
neighbors, at least in such a small tank.
Do you have a 20 gallon long tank, or a 20 gallon high? And what kind of
lighting? A normal 20 gallon long comes with a 20 watt flourescent bulb, I
think. If that's what you have, you've got only 1 wpg, which isn't a lot.
Even if you really have 25 watts, it's still not very much.
That is probably why your plants aren't doing well -- not enough light. The
swords might be okay, because they get big and your tank isn't very high (if
it's a 20 long). They'll be able to get right up to the lights.
You should have your lights on about 12 hours a day. Cut back on the
fertilizer. With your lighting levels, you may not need any fertilizer at all.
I don't think you can use the "fertilize the plants and they'll out compete the
algae" method. You don't have enough light. You might be better off choosing
plants that are suited for your lighting level and making sure you are doing
regular water changes.
How big are the gouramis, BTW?