A Little Atempt At Myth Busting

[Dave Spencer]

Your analogy with the bears doesn`t quite ring true, Neale. Grizzly and Polar bears are close cousins, whereas plants are and algae aren`t. I see what you are driving at, but plants and algae are no more in competition than Lions and Meerkats are.

The observation about a large, healthy plant mass being instrumental in combatting algae is one that rings true with most of us, and I agree that the mechanism here for algae suppression isn`t understood. However, I believe that algae is an opportunist in this situation, and will appear once triggered by a given signal. In the case of BBA or staghorn algae, we can easily deduce a strong triggering mechanism with the use of CO2. If I turn the pressurised CO2 off in my tanks then these two type of alga quickly appear. Switch the CO2 back on, and they slowly fade away. Most types of alga can actually be triggered with CO2 one way or another.

The thing to consider in this instance is why do different types of alga appear at different times. With a constant, but limiting supply of CO2, I see Spirogyra appearing, not staghorn or BBA. If I start a new tank, I see brown diatoms, yet, if I start one with Zeolite in the filter, they never appear. This is an easily repeated experiment, which leads me to thinking ammonia could be a trigger for this type of alga, not silica as I originally thought.

The point I am trying to make here is that whilst none of the above is done under any kind of rigorous scientific process, the deductions made through a little experimentation and observation can stand strong in this hobby, without need for professional citation. Most of what I have done to discover for myself has initially been motivated by one or two other people, rather than anything remotely pioneering on my part. I do actually love science, and come from a technical background, but I still treat planted tanks as a hobby, not a science.

I fully understand and appreciate your stand point regarding all the “myths” I have mentioned on this thread, but I have labelled them myths from the standpoint of my observations and many people from other certain, notable forums. Putting my head on the block, I am going to say that there is scant evidence to refute anything I have written in busting the myths outlined by me. I accept that these may well become myths that are busted in the future by someone, but in light of current knowledge they stand firm.

More thought should have been put in to the “plants supporting their own weight” myth but, nevertheless, the often written sentence “you can tell if a plant is non aquatic because it can support its own weight out of water” still remains fundamentally flawed, and shouldn`t be used.

Your point on some plants needing high intensity light is something under close scrutiny too. A while ago I would have been with you on this point regarding Hemianthus callitrichoides, but it has been shown by others that CO2 is more key here than light of any particular intensity. Myth busting for the future methinks.

P.S. feel free to use my name, rather calling me the original poster.

Keep up the quality posts Baron von Bubba, Andy et al. Thirty plus posts in and only one pointless one liner so far.

Dave.

 

[three-fingers]

Indeed .

 

[SuperColey1]

I don't think what we are saying r.e. lights need changing yearly is that they still 'function' after a year.

What we are saying is that this was a statement made when lights weren't so good, when ballasts were all magnetic etc. The lights degraded noticeably (Not the human eye but by PAR testing) over a year and therefore needed replacing if the user wanted to maintain the light at a certain range. It also meant that as it degraded the intensity degraded and penetration fell.

This is probably another of the reef world's rules that has just been transferred over to the planted hobby.

The trouble with this statement though is that tubes have moved on. A T12 today is much better than a T12 30 years ago. It will last longer.

Also the old magnetic (electric) ballasts are being used less and less as electronic ballasts become cheaper and cheaper. Magenetic ballasts that flicker start the tube 'wear' the tube out quicker. They waste more energy in starting the tube and therefore the old yearly change may well ring true here whether it be T12, T10 or T8.

With the electronic ballasts it is suggested that the tubes will degrade on average 5% (T8 or T5) at 40% of their life. On the conservative side we would be talking about 8000 hours here and that would mean if you have your lights on for 8 hours a day they only degrade by 5% after nearly 3 years of use. How they degrade after that point I don't know, they may fall of pretty quickly or slowly continue degrading.

So the point is that modern tubes (even on old sizes) plus the increasing use of electronic ballasts (Juwels use these in their I bars) mean that the tubes do not need replacing yearly. I would suggest even 3 yearly for the 5% loss is a bit of overkill.

AC

 

[nmonks]

I confess, I don't replace my tubes until they've either died, take ages to start up, or have weird dark rings around the connectors. In the big scheme of things, I think you're probably right, replacing tubes every 6 months or every 18 months doesn't appear to make a huge difference. It's obviously a good thing environmentally to make tubes last as long as you can before you throw them out, so I for one would encourage people to think along those sorts of lines.

Cheers, Neale

 

[lljdma06]

Hi Neale,

So happy to see you here!

Nice debate but to be honest, I have nothing to contribute. I just try to grow plants and don't really have the time to think about the "whys" anymore.