[Sneaky]

MyBird
- Bettas are suitable for "coldwater tanks" of around 76F.
Many many people keep them as such.
Yes they are a tropical fish, but in winter in their native lands
temps drop well into the 60's. Most people with coldwater tanks
do not keep their tanks below 74-76F, as they dont keep their houses
below this. I have yet to meet any person who allows their house
to get below 74-76F.

Your 10g tank with 6 kuhli loaches and a betta is overstocked
unfortunately. Kuhli loaches grow to be 4 inches each - so 24 inches
just for the kuhlis alone. Your filtration however is plenty adequate
for the stocking you have if the tank is also heavily planted.
Myself, I wouldnt put kuhli's in a 10g, but thats just me. I know
many people who do. In my opinion, they are best suited
for tanks 20g or larger.

Springer - The green stuff on the sides of the tank is algae. If its hard
to get rid of with a sponge, its beard algae. There are some fish who
will eat it, none of which are small enough for 10g.
Ghost shrimp and cherry shrimp will eat it, but would be eaten by many
kinds of fish, including goldfish.

Hagens Cycle is a waste of money. It does not actually contain
live bacteria, and when I first setup my tank during the cycle I dumped
literally bottles of this stuff in and it did absolutely nothing.

The only bacteria product on the market that is proven to help cycle
a tank is Biospira. It contains Live bacteria, and is kept in the refrigerator
section in pet stores that carry it.
Stresszyme, Biozyme, all those are only enzymes that stimulate the growth
of live bacteria, and its unproven how well they work.
In a stable tank you will never need to add anything like this anyway.
Not unless you overclean your tank, or clean your filters and tank at the
same time, which you should never do anyway.

Finally I will address a qoute by MyBird here:
"Try a scraper or razorblade, that's what we do Part of the reason you have such a large problem with this is that your tanks aren't clean enough."

Yes, a dirty tank can have algae problems, however, this is not always the case. 90% of the cases in which tanks have severe algae problems, it results from having too much light in the tank, and nothing to compete with the algae.
In order to prevent algae blooms, there are several stages to getting rid of it, cleaning the tank is only 1 of them.
In order to completely prevent algae, you must:
1) Keep the tank super clean
2) Reduce light amounts
3) Add live plants to compete with the algae
4) Reduce feedings of the fish and plants with fertilizer
5) Ensure that your water or plant fertilizer does not have phosphates
in it.

There are many causes for algae growth, none of them pinned down
to one certain cause. Its very hard to generalize on algae.
Even in my super clean 10g tank, with creatures that devour
algae, and super heavily planted, I still get algae growth.
This is because there is a small amount of phosphates in my
tap water, which is just enough to keep the algae growing no matter
what I do to the tank.