Re: Anthony on Leggy Plants

["Adam Shaw" <adams1 at comcen_com.au>]

Well Anthony, I think I was having enough debate on the uses of flourish
at the time :):) I may add another debating topic by posting this but ..
what the heck! First - the short answer (since I was *going* to comment
on this anyway but got sidetracked...)

The short answer is 'probably' (to the crappy lighting and old tubes).

The long answer is........ 'probably but not necessarily'!

Most people would err on the side of safety and agree that regular tubes
generally are good for 6 months. That is the time at which nearly all
tubes should be useful (those that are the right colour temp etc that is
to start with). However, there are many tubes out there on which
manufacturers 'claim' that their tubes have a life of, and *will*
operate for around 20,000 hours (or 2 years approx) (with quality
control gear, i.e. ecg), with only around 10% loss in luminosity over
this time. In fact, NEC Japan (or at least, the distributor in
Australia, or something... hmm) has been willing to stick their neck out
and put a whopping 5 year warranty on their D/HG 6700K triphosphor tube
and claim that over those 5 years the tubes will only lose 14% of their
output! It is at this point where I add these comments;

'Luminosity' - Whilst the manufacturer's claim that the output might
only drop by 10-15%, one could speculate as to what parts of the
'useful' part of the light spectrum is lost over that time? Scott made a
very interesting post in issue #44 on fluorescent lighting and other
options, where he added comments on the 'useful spectra' of light. Is
the useful r,y,o,b spectrum lost, or the useless green spectrum over the
life of the tube? Who knows, without performing tests over the full
20,000 hours.

So, like I said before - the short answer is 'probably', and I would
personally look to it as a highly probable source of the problem. On the
other hand however, I have had tubes last 18 months before I got around
to replacing them, and even slightly longer than that - and with great
growth on even moderately to hard to keep happy plants right up until
that time. I would say it would depend on the particular brand and
quality of the tube itself. 6 months in my personal opinion is more of a
'safeguard' than anything. I would say that is more of a benchmark past
which nearly all tubes should make before needing replacement. 18 months
would definitely be kind of when you'd want to be well and truly changed
by however I believe.

This may start a new series of debates but hey... Only speaking from my
experiences etc. Personally, if a manufacturer is willing to place a
warranty like that on a tube, one would tend to think that it would at
least make it well past the 6 months mark :) It would depend what tube
that Rachel was using, the quality etc I would say...

So, in closing, I agree with you - but just wanted to throw these above
thoughts out there in the open anyway just saying 'not necessarily', and
'personally I'd hate to spend the money to replace a whole heap of tubes
after *every* 6 months - so, I don't, and my plants are fine for the
most part'. I just question the notion of 6 or even 12 month ritualistic
replacement of what could quite possibly be good tubes I guess. One
would assume however that if everything *else* seemed good, then the
tubes would be a relatively safe bet to be the cause... There were other
issues here though as Tom pointed out (and I tried to, but my inferior
plant knowledge compared to Tom made my posts look like speculation
rather than wisdom - hmmm, a pattern emerges.. haha!).

My 2c, as usual.

Cheers,
Adam Shaw
Australia
----------------------
Original Message: 

Date: Wed, 5 Feb 2003 10:54:53 -0800 (PST)
From: Anthony Law <sulfur at yahoo_com>
Subject: Re: Leggy plants 
(Rachel was wondering why all her plants are leggy. 
Adam & Tom asked about macro & traces dosage, etc)

Ok I've followed this entire thread with interest but
am surprised nobody commented on this:

> The tank is a standard 72, not unusually deep. The
> tubes are about 18 months old. There is canister 
> CO2, which I forgot to mention - that's why the pH 
> is where it is.

I thought regular tubes are good for 6 mths & PC for
12 mths.  So your 4x55W PC will have very little
intensity left after 18 mths!

Sounds like you're dosing a ton of nutrients & CO2 but
giving them crappy lighting.  No?