Graeme Edwards said:
Why should simply raising Co2 ppm have such a huge impact on the production of algae or lack of? Is it down to plant growth - plants start growing harder, so thus out compete with the algae? Is it as simple as that? What if you crank your Co2 up, but have a low bio mass. Are you not worried about fish at this point.Where do you draw the line. Are we looking at fish health, grow rate, flow rate, lighting and biomass all at one point to asses what the required action should be? I say yes.
Im simply asking the questions that many wish to know.
Interesting points about trimming plants and open cuts, it all makes good sense to me.
Oooo, OOOooo! I know this one
1. Do you see algae on new tips or older leaves?
Older, takes time for bacteria and algae to colonize.
Fast growing weeds= less algae as you can trim the tops and toss the lower infested parts.
Also, as new growth fills in, the algae gets shadowed(less light).
Less light = less CO2 demand and less algae growth, because algae are not CO2 limited to begin with........
CO2 variation makes for a good signal when to grow for an algae spore, means there's a large shift/change in the system (some is rotting and releasing nutrients, decaying etc, and or something is not using up the CO2 like before).
Both good seasonal change signals.
But plants need huge amounts of Carbon to grow, algae simply need very little.
If you limit CO2 and have high light, plants slow or stop growng, they get progressively smaller tips. Now they are pretty much like rocks and driftwood, just substrate for algae to grow on.
It takes time for the plants to retool their metabolism and get going again once they have been limited. They wait and will start new growth again after some time of good stable conditions. The old growth is general sacrificed(they are fast growing weeds and go up to the surface and block light below to gain the upper hand).
Algae have no issues with retooling because they are small single cell and have no limitations.
NH4 is one item that seems to induce algae, but CO2 seems a larger reason.
These are the only 2 chemical parameters I know of and can confirm.
But.......this is not all about chemicals...........there's light involved here and few folks bother to measure it for comparison. This maybe changing soon.
Other issues are indirect: "I forgot to clean the filter and it reduced flow way down and has loads of flith and organic matter........" I did not top off my aquarium due to evaporation loss and the flow degassed a lot of the CO2".........I assumed my CO2 was fine based on a test kit/method"
These are human social issues..........that often are over looked. Folks get tunnel vision with nutrients.
Better to focus on CO2 and hedge your bets with low light, good general care, current, water changes, pruning, adding ferts to both the water column and the sediment etc.
This makes errors much less and takes off demand on nutrients/CO2.
Growth is slower, but the likelyhood of alga is greatly reduced.
Plants can and do respond to changes in our aquariums, and in nature, but generally they are much slower lumbering beast. Takes them awhile to gear up with enzymes(Rubsico particularly- it's the wolrds most common enzyme and the largest one in aquatic plants), transportation within the plant, allocation of resources to where they need to be.
This takes time, and algae have no such issues, they do not need to make large carbon based stems, leaves etc.
Plants do and at a much higher demand and have a much lower surface to volume ratio than algae(makes uptake harder).
Algae are also generally fleeting..........they do their thing and produce spores having completed the asexual/sexual spore lifecycle/s. Sort of like annuals(algae) vs perennials(plants) ecology.
Also, healthy strong plant growth = lots of O2= lots of good fast cycling by bacteria, as well as good uptake by plants. These guys work togeher, when you stop plant growth, you stop adding the O2, the sediment "dies", roots stop pumping O2 down there, the bacterial colonies slow and whither............You can do this easily by reducing/limiting CO2.
These are secondary effects, but play roles in algae it would seem to me.
Good sediment establishment and health plays a large role I think.
It's not just bacteria however, it's a complex of roots and plant health, as well as waste loading from fish, shrimp, plant decay, driftwood, detritus, tannins, and...........bacteria and other tiny microsopic critters/inverts. If this is short circuited..........then things fall apart and take time to reestablish.
Small changes are less of an issue, large uprooting without care/water changes often lead to algae.
Stopping plant growth by 10-20X correlates into 10-20X less root growth and O2 production.
Aquatic plant tank sediments are pretty aerobic mostly, this is due to the plants' roots.
In natural systems, they do not like a lot organic matter which causes low REdox levels, if you stop growing roots/producing O2, those redox levels become worse for plants(they become more negative), and adding more OM(organic matter) reduces it even more as roots rot from lack of O2 etc. They need some OM to help cycling and bacteria need their carbs just like us....but not too much, nor too little.
10% to perhaps 1% is good for OM.
Reduced carbon is the heart of all things sediment and bacterial.
Once you realize this and how plant roots behave, all the heating cables, power sand talk makes little sense. That's Engineering talk and yammering, not botanty or plant biological talk. Microbiology is part of this as well, but not quite as much as some think and a lot more than others think.
Tropica raises their plants in sterile hydroponics culture, no CO2 issues(air gas phase sources), so no light , CO2 or nutrient limitation issues nor bacteria.
Fine for plant production, but not for fish, we want water
A side note is that 90-95% of all nursery container plants are grown pretty much the same way as hydoponics using fertigation water, and soiless media in the pots(generally bark and sand for weight and to hold the roots).
Regards,
Tom Barr