# Grain size of substrate for Crypts? Help appreciated.



## JRJ (Feb 9, 2005)

I changed the substrate in a 75g from regular Flourite to Flourite Black Sand at the end of last year. The grain size of the Black Sand is extremely small, I wouldn't even call it sand, but rather dust. So far, the growth with it has been very disappointing, to say the least, especially compared to the regular Flourite where it was excellent.

I've also used Onyx sand which has a smaller grain size than regular Flourite, but not nearly so as the Flourite Black Sand. I moved some C. lucens, that was 5-7 inches tall, from the Onyx to the Black Sand and in four months it has shrunk to barely 2 inches.

What gives? I thought most crypts were from environments with lots of fine sediment.

Thanks,

Russ


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## Yoong (Nov 26, 2007)

In my opinon. Powery substrate is not a good idea. They are so fine and well packed together that there is barely and gaesous exchange at the bottom of it. Hence oxygen exchange is poor and soon anaerobe respiration(rotting) will start, leading to root rot.

Crypts in the wild do live in environment with sediments. But a lot of them the sediments are loose and soft. Besides, there are often underground water movement in the nature.


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## ts168 (Apr 13, 2004)

It also depend on what type of cryptocoryne you are talking about.
If you are talking about the usual cryptocoryne propagated from the nursey lab, then normal snad will do. 
Infact most of my crypt i grow them in sand, and some blackwater crypt will need different type of Substrate...
using artificial color sand might not be good to your crypt.
I think commonly crypt grower in europe use sand, akadama ...

May the expert there share their choice of Substrate...

Here a list of substrate i have use for now. will continue to add whenever i came across any....
http://www.cryptgarden.com/www/article/others/substrate.html


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