John. I'm pretty sure these are planaria, which
are flatworms and members of the Platyhelminthes
are often found in aquariums with uneaten food.
The planaria won't hurt the fish, but they are
a symptom of too much gravel containing too
much uneaten food, and that is not good for
food causes all sorts of problems, and uneaten
food in your aquarium may have been part of
the reason that your mollies died.
Clean Your Aquarium. Click
here to read about Cleaning Your Warm Water
Aquarium. In particular you should clean your
gravel with a Gravel Washer. Click
for more about a Gravel Washer.
Add Aquarium Salt to your aquarium up to a maximum
of 1 Tablespoon for each 5 gallons of water
in your aquarium. I seem to remember you have
a so-called 29-gallon aquarium, which probably
has about 25-gallons of water. If so, you should
add a maximum of 5 Tablespoons of Aquarium Salt.
If, for example, you already have 2 Tablespoons
in your water, add 3 more Tablespoons.
Don't Over React. Clean your gravel every day
with the Gravel Washer. When you've removed
20% of the water, stop and top your aquarium
back up with tap water from the faucet.
In your case 20% of 25-gallons = 0.20 x 25 =
5 gallons. Repeat this procedure every day.
It may take several days of gravel washing to
get your gravel really clean. When it is finally
really clean, begin removing gravel, until it
is at most 1/4" deep. If you have an undergravel
filter, email me back, because you'll need some
more advice, or click
here to go to another website with information
about how to remove an undergravel filter.
Add Quick Cure. Each day after you clean your
aquarium and wash the gravel, treat the water
with 1 drop of Quick Cure for each gallon of
water in your aquarium. In your case this will
be 25 drops once a day each day. Click
here for more about Quick Cure. You can
also replace the Aquarium Salt that you removed,
which would be 1 Tablespoon in the 5 gallons
Small fish such as baby mollies might eat the
planaria. I would try adding a few small fish
to see if they will eat the planaria.
steps 1 to 6 listed above, until you don't see
the worms any more. This procedure will take
several days and require quite a bit of your
elbow-grease, but it's the safest method for
the rest of the fish in your aquarium.
hope my comments help you. If you have a follow-up
question, please send me an email reply. Good
luck with your fish.