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Re: Scarlet Hygro and slow growth of plants without water changes

"Alysoun McLaughlin" <alysoun.mclaughlin at ncsl_org> wrote:
> The other (I forget what it's called) looks just like giant hygro, except
> it's got a brilliant scarlet color.  It looked great, but it just didn't
> grow.

Ca shortage can cause this.

> After I clipped it, the leaves started to grow, but were stunted, rounded
> and twisted.

stunted, twisted leaves is a symptom of calcium or boron deficiency.

> For what it's worth, my other plants are doing well.  Explosive growth of
> the rotala, as long as I do water changes on schedule.  Skip a week, and the
> growth all but stops.  pH has been around 7.  Liquid fertilizer doesn't seem
> to be having any effect at all

Growth being stimulated following water changes indicates a shortage of
a mineral (calcium?) which is present in the water change water.

You have all the classic symptoms of a shortage of calcium. I always use
calcium carbonate even if it dissolves slower than CaCl because the high
amounts of calcium required would create "salty" water if I had to use
CaCl. The growth spurt following a water change indicates that your
plants are totally reliant on the tap water for calcium and running low
between water changes. pH of 7 without CO2 injection usually indicates
soft water (low minerals). Whatever it is you're missing is not in the
liquid fertilizer. Its really not feasible to dissolve calcium in
concentrated fertilizers such as PMDD or other off the shelf products.
The anion used with the minerals is often sulphate and this will cause
calcium to precipitate if a strong solution of CaCl is mixed with a
strong sulphate solution (i.e. PMDD).

Alysoun, I recommend that you test your water to ensure that you have at
least 50 mg/L of calcium carbonate (CaCO3). A good target to shoot for
is 80 mg/L CaCO3. You can achieve this by using 5 to 10 ml of CaCO3
added to 50 litres of water. A household 5ml spoon of finely powdered
CaCO3 weighs somewhere around 4-6 grams.

Roger wondered about all my huffing and puffing on the subject of GH. I
confess to two motives: 

1) I want to motivate change and dramatizing the issues helps to get
people to think about it and to actually speak out about it 

2) there's a certain level of good-natured teasing ;-) I sure hope I
don't offend anybody especially with a few Canada-US puns. 

My strategy for change is to influence folks on the APD and indirectly
to influence the manufacturers. I believe that if we make our views
clear on this forum that the test kit manufacturers will follow the
applaudable lead set by Dupla in their _Mineral Concentration Test
Kits_!   :-) 

Please note that I did not use the H-word anywhere in this post!! I
intend to ban it from my website. I'm debating severing diplomatic
relations with other websites which have a poor record on H... issues
however since this didn't seem to work with the Castro regime, it might
be a bit too extreme. ;-)

Steve Pushak                              Vancouver, BC, CANADA 

Visit "Steve's Aquatic Page"      http://home.infinet.net/teban/
 a mineral sensitive web site.