Seaweed cultivation is underdeveloped in Baltic countries because low salinity reduce seaweed growing efficiency. Seaweed grown in brackish water have adapted to low salinity and their physical demands are different than seaweed growing in ocean water. Therefore, there is a need to determine best cultivation parameters that would favour brackish seaweed cultivation. The effects of nutrient loading and different lighting colours were assessed on the growth and morphology of the abundant filamentous green algae Ulva intestinalis, collected in coast of Latvia. Conventional fertiliser and special algae growth media was used in different concentrations and growth rate was measured. Different lighting was tested: normal lighting, blue, red, partial lighting and no lighting was compared, and growth rate was measured. Results show that plant fertilizer gives highest growth rate 3.4%/day in concentration 2.5 mLL-1 comparing to Provasoli Enriched seawater medium which gave highest yield in 5 mLL-1(1.70%/day). Full light conditions show highest growth, other researched light regimes cause fragmentations of algae material and leads to loss of viability.