According to the
tropica website all the below species will be ok in tanks of 15C
Sam
Aponogeton crispus
Aponogeton madagascariensis
Azolla caroliniana
Bacopa australis
Bacopa caroliniana
Bacopa monnieri
Cardamine lyrata
Ceratophyllum demersum
Ceratophyllum demersum 'Foxtail'
Ceratopteris cornuta
Cladophora aegagropila
Echinodorus 'Ozelot'
Echinodorus 'Ozelot' (Green)
Echinodorus 'Red Diamond'
Echinodorus osiris
Echinodorus uruguayensis
Egeria densa
Eleocharis acicularis
Eleocharis ''parvula''
Glossostigma elatinoides
Gymnocoronis spilanthoides
Hydrocotyle leucocephala
Hydrocotyle verticillata
Juncus repens
Lilaeopsis brasiliensis
Lilaeopsis mauritiana
Littorella uniflora
Lobelia cardinalis
Ludwigia helminthorrhiza
Ludwigia repens
Ludwigia repens ''Rubin''
Lysimachia nummularia 'Aurea'
Monosolenium tenerum (''Pellia'')
Myriophyllum aquaticum (Green)
Nuphar japonica
Proserpinaca palustris ''Cuba''
Riccia fluitans
Riccia sp. ''Dwarf''
Salvinia natans
Samolus valerandi
Shinnersia rivularis 'Weiss-Grün'
Vallisneria spiralis ''Tiger''
Vesicularia sp. ''Christmas''
Vesicularia dubyana