Are the snails eating holes in them?


Snails eat dying plants.

Would I benefit with getting a CO2
system for my malawi cichlid pH 8.6 tank? I heard it lowers pH.

You heard right. But is pH the issue?
Most of Malawai ain't that high, it varies location to location and
the fish from there are easy to bred and unless you are getting
sensitive wild caught fish. The salts are still the same, everything
else in the water is the same, only the amount of CO2 is changed and
it affects the pH.
The hard water etc is still hard.
That's the main thing the fish concern themselves with.
pH variations due to CO2 addition have no effects I've seen on rift
fishes.

You will likely need to drop the pH to about 7.4 or so if you have a
KH of 15-20 etc. Parts of Malawai are close to this pH.

I am going
to get a puffer in a few days to control the snails (my old one died) but
I'm wondering:

Puffers, SAE's CAE's, plecos ? You sure this is cichlid tank?:-)

1) what can I do to control the algae?
2) do I have too much/too little light?

Too little.
Algae control is more/too complicated to explain here. Basically, if
you have good dense plant growth, you don't have algae growth. When
the plants are not growing well, the algae will.

3) should I get C02 injection?

If you want plants under water, it's a good idea.
Floating plants will do very well though.

4) should I adjust my photoperiod more? (the tank gets additional light when
my roomates leave the lights on at all hours of the night, but those are
compact florescent bulbs for our living room so it shouldn't be providing
the right spectrum for plant growth)
5) what can I do to control the holes (some look like burns) and wilting?

Give the plants what they need to grow.
Light , CO2 and nutrients.
Floating plants will have enough light and plenty of CO2 from the air.

Regards,
Tom Barr