Jerry, Aquatic crinums need more than just gravel (or rockwool). As opposed to many aquatic plants that can largely subsist off what they absorb through their foliage, aquatic crinums have an extensive root system and need soil (or a nutrient-providing substrate more generally). I've had good success using 3-4 inches of plain old topsoil under a thin layer of sand and an inch or so of gravel (the sand and gravel function merely to keep the soil from being disturbed by water flow). Place the bottom of the bulbs at the top of the soil and beneath the gravel. If your water stays in the upper 70's I think that's warm enough. Basically, grow these plants like you would any land based plant. Would you try to grow a garden crinum in nothing but gravel or rockwool and expect it to thrive? You might also want to try aquatic plant fertilizers. A submersed setting maximizes leeching of soil nutrients so even if you use soil initially, you'll need to start supplemental feeding eventually. -|<ipp > From: Jtlehmann@aol.com > Date: Tue, 8 Mar 2011 22:51:53 -0500 > To: pbs@lists.ibiblio.org > Subject: [pbs] Aquatic Crinum > > Can aquatic Crinum be converted, partially or wholly, to non-aquatic > culture? If so, how? If not, what is the best culture for long-term growth? > Mine only seem to last about one year before slowly dying back and then just > never coming back to life...and then they just seem to disappear. They > never bloom, but initially grow very well. No fish, a few small snails but I > remove the bulk of them when there seems to be too many. I don't have a > heater in the tank, but the room temperature is warm: 70s - 80s F during > the day, with about a 10-degree drop at night. Plenty of light! They are > secured in the gravel if they are loose bulbs, otherwise they are in the > small plastic pots filled with foam-like material. There are a few other > aquatic plants in the tank with them, nothing special as they are all easily > obtained at pet stores, but have become more interesting to me than the fish; > the aquatic plants are residual from my "fish days." Any suggestions would > be greatly appreciated! > > --Jerry Lehmann > > Olathe, KS > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/