Lighting + Photosynthesis

[liamsart]

My 3 week old tank is 96litres (just over 20 gallons) and it is lit by 2 x 20W bulbs with reflectors. At present it contains the following plants....

Alternanthera reineckii
Elodea
Echinodorus compacta
Hygrophila polysperma
Vallisneria am.
Limnophila sessiflora

Im hoping to add plenty more plants, but I was wondering whether it has sufficient lighting. It also has DIY CO2 injection, but there is no sign of any photosynthesis cos I can't see any pearling. The plants have certainly started to grow quite rapidly, but I was also wondering if photosynthesis can take place without there being any evidence of O2 bubbles.

 

[mrV]

Water absorbs light alot, so you probably want to change those bulbs to fluorescent tubes. F-tubes give more light than bulbs and they do not heat water so much either. Don't buy more plants before you see, do they grow at all or do they die from shortage of light. And do the bottom leaves grow too, or do plants only stretch toward light.

A. reineckii needs lots of light, CO2 and liquid fertilation (iron) to grow.

The plants have certainly started to grow quite rapidly

If they seems to stretch and leaves are small/few, then you have too little light. Bulbs works ok too, if the tank is small (not so high). If you want to add more / alot of plants, I recommend to change those bulbs to f-tubes (maybe couple 15/18W tubes).