Re: E.Quadricostatus and other chain swords

>From: KB Koh <KB_Koh at ccm_ipn.intel.com>
>Date: Thu, 16 Nov 95 12:30:00 PST
>Subject: How to shorten E.Quadricostatus
>I've got tired of my tall growing E.Quadricostatus. They are about 
>15-20cm tall, some taller than my E.Amazonicus.  I need it to grow less 
>than 10cm. I saw the same thing at the fish shop and their runners are 
>less than 5cm tall. It must be the CO2 as the shop do not inject any 
>CO2. Someone please advise me how make it grow shorter. Don't tell me to 
>use E.Tennellus because the shop are not selling them over here. Thanks.

Are you sure that you have quadricostatus? In the table presented below are
some measurements of four chainswords which I have grown under different
condtions. I think the best indicator for quadricostatus is the width of the
leaves. I have not yet been able to grow quadicostatus as tall as yours, and
wonder if yours can be the tall variety of tenellus or something similar to
the one I call 'unidentified.' Unfortunately,  I have not studied all
combinations of substrates, lighting intensity and use of CO2, so I hesitate
to comment on the effect of CO2 alone. 

Table 4.	Dimensional information of chain swords grown submersed in my
 by various cultivation conditions (for a 'typical' plant).
						    Cultivation Conditions
		      	TANK No. ->		 1		2		3
			|Tank size(liters)	300		120		280
			|Lighting (watts)       160	        20		80
			|Substrate	        soil		peat		peat
			|Use of CO2	        Yes		No		No
Chain sword type

'pygmy' chain		Leaf length (cm)	12		16	    3.5-12
E. tenellus	 	Leaf width (mm)	         2		2.5		1-2
 var. tenellus		Number of leaves	27		16	    12-32
'narrow leaf' chain	 Leaf length (cm)	15		11		9
E. tenellus 		 Leaf width (mm)	3.5		 3		4
   var. parvulus	 Number of leaves	21	 	16		18
'wide leaf' chain	 Leaf length (cm)	11		-		2.8
E.quadricostatus	 Leaf width (mm)	10		-		6
			 Number of leaves	14		-		14
Unidentified chain	 Leaf length (cm)	27		-		-
('long narrow form')	 Leaf width (mm)	 4		-		-
			 Number of leaves	23		-		-
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