[jaliberti]

While googling "float crypt plant" in order to determine if certain crypt species could thrive without substrate I found a link which mentioned, but did not elaborate on, "rainwater crypts."

I then googled that term but the only result was the aforementioned link. Which crypt species could be considered "rainwater crypts"?

I maintain several bare bottom tanks of peat treated rainwater with pH levels between 5.0 to 6.0 and over the years have killed more plants than I care to admit. At the moment I have no plants whatsoever but am considering adding some low maintenance crypts, if such crypts exist.

Which plants, if any, can thrive (surviving isn't sufficient, I want them to thrive) in very soft, acidic water without substrate? Which crypts could be considered "Blackwater crypts"?

If floating wouldn't be ideal I'd anchor down rhizomes/roots like is done for Anubias.

Thank you!

 

[dpod]

Honestly, I think you're barking up the wrong tree looking for crypts that can survive without substrate. While they can survive floating for a short while (weeks at most) they're going to suffer from it. If you want to keep the tank bare-bottom, how about planting the crypts in small dishes of sand or gravel? Anything that's more an inch or more deep and two inches wide should be enough for most smaller crypts.

 

[Grubs]

One of the wholesalers here in Australia is selling "crypts on wood" where crypts are treated very much as you would Anubias. So it works. However I think there is a big difference between being "bare rooted" in a planted tank with plenty of fertilizer in the watercolumn vs a tank full of rainwater. There are certainly crypts that live in hard water and others that live in soft acidic water, but IME all crypts are gross feeders and if you try fertilizing a non-planted tank for the benefit of a couple of crypts you're going to end up in algae hell (or in a room overlooking the gates).