Growing peace lilies in a Betta vase with water makes an attractive display of foliage without the hassles of potting soil and plant pots. Although it is not recommended that you grow Betta fish in the water with peace lilies (because the environment is not generally suitable to sustain healthy fish) they are often sold together for this purpose. Whether you choose to add the Betta or simply grow your peace lily in a vase of water with decorative stones, peace lilies are well adapted to growing in water without soil.
Purchase a Betta vase with a plastic insert to support the peace lily. Inserts of clear plastic that sit in the mouth of the vase keep foliage from slipping into the vase. They may need to be trimmed to the appropriate size to accommodate the roots of the peace lily.
Remove the peace lily from its pot and shake gently to remove excess soil. Wash the roots to remove all traces of soil. Soaking the roots for 10 to 15 minutes in room-temperature water will loosen soil and make it easier to wash away the remaining soil. Any soil left on the roots will cloud the water and ruin the appearance of your vase.
Fill the vase with filtered or distilled water. Water should be at room temperature to avoid shock to the roots of your peace lily. Add decorative stones or glass nuggets to the bottom of the vase, if you prefer.
Slip the plastic insert over the roots of the peace lily so the base of the plant rests in the cavity created by the insert and the roots extend through the bottom. Place in the mouth of the vase with roots hanging down into the water and foliage erect above the vase.
Place in an area that receives filtered light. Direct sunlight damages foliage and heats the water, resulting in damage to the plant. Keep peace lilies 5 to 8 feet from windows.
Change the water once or twice per month, if it becomes cloudy or appears stagnant. Top off every few days to replace lost water and keep roots covered with fresh water. If you do not have Betta fish in the water, a weak solution of water-soluble fertilizer mixed to one-quarter strength provides the added nutrients your peace lily needs.