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Re: Aquatic Plants Digest V3 #189



Subject: Re: Nothing under the gravel

George wrote:

>I have no trouble believing a substrate free of additives will support
execllent 
>growth. 

<very big snip>

>The high tech approach is [un]naturally better "balanced" since we
actively do 
>the balancing by throwing money at the problem.  WE control the pH, WE
control 
>the nitrates, etc. 

_Excellent_ post, George, you've out done yourself both in diplomacy and
insight!<g>

------------------------------

>Subject: Metal Halide
>
>    Good evening! I was curious; is there a vast difference between metal
>halide bulbs other than the wattage? I guess what I want to know is if there
>is a "wrong" metal halide to buy. And, most people say that to have a
>successful planted tank you need to have at least 2 watts/gallon. However,
>the lumens that a metal halide produces is at least 4 times the amount of
>any incandescent or fluorescent bulb. So, does the same 2 watts/gallon still
>have to be adhered to? Thanks.

Actually MH and fluorescents are nip and tuck when it comes to lumens per
watt.  Normal fluorescents are slightly lower, energy efficient T-8's are
slightly higher.  All are _far_ superior to incandescent.

And, yes, the 2w/g guideline does pertain to MH's too.

------------------------------

Subject: hard water / peat substrates

>I recently read that the addition of peat would render
>the chart many people use to determine CO2 concentration
>by measuring water hardness and pH to be inaccurate. This
>makes sense, because peat moss only lowers pH and not
>water hardness... doesn't it? 

It does both.  But it is the fact that it releases humic acids (thereby
lowering the pH) that interferes with the charts.

------------------------------


Karen Randall
Aquatic Gardeners Association