Introduction and questions

Thought it's time to introduce myself and my beginning attempt at a plant
tank. And take the opportunity to ask some basic questions. Thanks in
advance for answers. Feel free to advise.

Goldfish are my main hobby. Because they have moved up to larger tanks, I
was left an extra 10-gallon about two months ago, which I have set up to
try to raise plants.

Plant tank: 10 gal, heated to arond 76F
pH 7.5, 4 dkH, Nitrates at about 12.5 mg/l
Substrate: Two inches of black #3 gravel with laterite balls
CO2: DIY Yeast system through airstone into downturned end of a water bottle.
Light: One 15w PowerGlo
Fish: Three true Siamese algae eaters.
Filter: Simple sponge filter driven with air stone; also a separate aerator
Plants (don't know botanical names): 3 vals growing freely from runners
(over 16" long blades), 4 banana plants (two with big leaves and two
floating pads each), cardamine, pennywort, Java fern, 2 sword plants , 2
unknown (they have leaves on long stems growing out of a fuzzy brown tuber
somewhat like coconut hair). Watersprite is regenerating after most were
eaten by goldfish.

1. How can I raise CO2 concentration, which according to FAQ and charts
would be better for plants if doubled? I am considering moving the plants
to a 20-gallon soon. My tap water comes out pH 8.5, 4 dkH. The current CO2
setup lowers pH to 7.5 but I can't get it any lower. As it is, I lower the
pH of the change water with ascorbic acid (Vitamin C crystals--any
dangers?) before putting in tank.

2. How can I get the sword plants to grow more? They are offshoots of a
mother plant in another tank and seem stalled at 5 inches and about 8
leaves each. All other plants seem to be growing continuously.

I describe the plants in the goldfish tanks below in case anyone is
interested, especially in the tank with seemingly no nitrates. The plants
in these tanks are the only ones to survive the fishes' nibbling and

Goldfish Tank 1: 15 gallon, black ceramic bowl with 30" diam opening,
unheated (60F to 80F)
pH 8.5, Nitrates 0, 4 dkH
2 small orandas
2 inches of #3 black gravel
Filter: External Eheim canister
Lighting: sun only, in corner with west and north windows
Plants: Main plant is a rush of some kind in a 1 gallon dirt filled pot in
the middle of the bowl. Its roots run throughout the substrate and seem to
consume all the nitrates. Its leaves are 2-3 feet long. Also, two Java
ferns that don't do much and some struggling anacharis.

Goldfish Tank 2: 30 gallons, unheated (65F to 75F)
pH 8.5, Nitrates <12.5 mg/l, 4 dkH
1 large oranda, 1 small oranda, 1 small pearl scale
Filter: Biowheel 160
3 inches of #3 black gravel
Lighting: 1 20w aquarium tube (much cheaper from lighting store), 1 20w
warm white
Plants: Only surviving plants are Amazon swords, a val. and some
"micro-swords." The original val. (mother of those in the plant tank) was
moved here a week ago. It has 10 20"-long blades and is putting out a
runner already. The microswords don't do much and don't seem able to
establish roots, much less spread.

Greg. Tong
gtong at sirius_com

"Every infinity is composed of only two halves."