Nitrate/Phosphate experiment.

I am simply very curious as to the exact mechanism by which healthy plant growth defeats algae.

I kind of understand the low light aspect but I don't quite understand if you have the excess nuitients and light, what is stopping algae from growing at the same time as the plants?
 
Thanks Tom. I found the link between an algae outbreak and too much pruning, replanting, and stirring up of sediments to be particularly relevent in my case. These were definitely happening in my tank before recent algae problems, along with low nitrates (for some reason, the dark red of the nitrate color card always scared me a bit). Also seem to be doing better with more pressurized C02, but it's odd that with my former Aquasoil substrate and DIY C02, there was far better growth and no algae.
I guess that's why I was slow to increase my pressurized C02 bubble rate.
It's also very helpful to now think in terms of not having any algae germinate at all because the plants define or dominate the system, rather than the reverse.
 
I kind of understand the low light aspect but I don't quite understand if you have the excess nuitients and light, what is stopping algae from growing at the same time as the plants?

Do field weeds grow in the established forest?
Or only where's there's a nice opening?

Takes a few years to get the forest really chugging along.
Similarly, aquatic plants ....once they are chugging along and well established, dominate the system, much like a forest.

If you cut the forest down, it takes a long time and a lot of effort to restore it. Likewise, you remove all the aquatic plants, it much hard to restore an aquatic system. Nutrients and CO2 are the same in both cases.

Life history/cycle of weeds/algae are similar to the aquatic plants/trees.
It's a fairly normal thing, not that much mystery. Algae and plants compete, but not much and then mostly for light.

If you destroy the forest, say remove all the nutrients from the soil, will the leaves and trees do well? Not likely, over time some trees will die, some will lose all there leaves the weeds will appear because of gaps in the canopy.

Also, if you suddenly slow the growth of aquatic plants, they normally remove NH4 waste from fish and rotting/dead vegetation, tiny invert critters etc........and the O2 they add to the sediment drops and declines.
There maybe a link between the sediments, roots, bacteria and the algae perhaps. Not sure though.

So there's might be many different chains, cascades, indirect things occurring.

It's not direct, there's little evidence that it is, even in high light aquariums, I still have no algae, however, those tanks are much less stable and have less wiggle room, harder management.

But certainly are possible.

Still, it's generally not a goal for aquarist to have really high rates of growth. So most simply use less light, get away from HLD.

Some insist on high light and then wanna play this game with limiting nutrients to limit growth, which makes things tougher, not easier. Some suggest it helps with coloration this way, but not really, I have not seen it, I still get real nice color with lower light, so does Amano.

Still, the forest analogy works well for some to grasp the idea.
There's the elephant and mouse analogy as well, also a car and an accelerator/gas use.

Regards,
Tom Barr
 
Thanks Tom. I found the link between an algae outbreak and too much pruning, replanting, and stirring up of sediments to be particularly relevent in my case.

Myself as well, algae likely thrive where there's an intermediate distance level in the aquarium. Total disturbances, well, then you go from huge extremes, not much will live. Minor, not enough to "tip the scales", medium, enough to harm the plants just enough to have them grow, but not dominate entirely.

See Joe Connell's research on this concept(He's still at UCSB, saw him every now and then as I walked by his office, Dr Endler or Endler's liverbearer, he's down the hall as well, small world).
Applies broadly to many things, including horticulture and aquariums/algae, marine systems etc.
http://en.wikipedia.org/wiki/Intermediate_Disturbance_Hypothesis

Ecology is a bit more involved than many of the simple ideas the general public is exposed to, it's full of math and experimental designs. But these offer a lot of insight and interesting relationships that mat be missed otherwise.

Pretty cool really.

These were definitely happening in my tank before recent algae problems, along with low nitrates (for some reason, the dark red of the nitrate color card always scared me a bit).

Well, a calibrated test is the only way to test.
Otherwise it is just a guess.
May as well do EI.

If you do calibrate correctly, then you can test well and be confident in the data and not leave yourself open to bad assumptions(good ones are okay!).

I think there's some good papers out there on inverts and fish for NO3 toxicity. This one is useful and gives a wide range. Note that N-NO3 is 4.4x the reading for NO3 to account for the O3 on nitrate.

Guppies are pretty tough, but 800ppm of NO3 is pretty juicy.
I've gone to about 160ppm of NO3 before I saw any issues with Amano shrimp, but fish where fine, Discus, Roselines, plecos, most any catfish, tetras, Apisto's etc etc.

Shrimp are the best model for toxicity for us, and RCS are perhaps the best for this due to high breeding rates and measurable effects on brood production.

Fire reds, CRS are typically highly inbred, but are worth more $, so they are not willingly tested.

Same with Corals and other high value livestock.
So those tend to remain unknown......but reports come in where the ppm's are pretty high.

http://www.waterboards.ca.gov/water_issues/programs/tmdl/records/region_2/2008/ref2426.pdf

Also seem to be doing better with more pressurized C02, but it's odd that with my former Aquasoil substrate and DIY C02, there was far better growth and no algae.

Are you assumign that the ADA AS is the same nutrient content over this same time frame or was new ADA As used in both cases?
If not, then this is not a fair comparative test.

If so, it still might not be, since the CO2 might be enough in the 1st, but not enough, even though you have gas tanks.

It's the user most times, not the method or aquarium:o
Yes, we are to blame, the killers that we are.

guess that's why I was slow to increase my pressurized C02 bubble rate.
It's also very helpful to now think in terms of not having any algae germinate at all because the plants define or dominate the system, rather than the reverse.

Well, fear is real for folks.
Getting folks to over come this fear is a story old as the hills.

Once you look at this and see there's no reason for fear, then you tend to be a bit embolden. So folks then run around claiming EI is great etc......it may or may not be.

Depends on what the goal is really.
Tweaking and modification for one's goal is a lot of it from there, but at least you have a simple easy to use standard for CO2 enriched aquariums.

Excel dosing and non CO2, sediment rich methods etc, also offer a great deal of management options and really much better results than many assume.

The key point is really to learn several methods so that you can offer experience and help no matter what the goal might be when another hobbyists comes along. No one method will be all things to all people.
So the more bags of tricks and tools you have, the more help you can offer.

Same for test and comparing different methods.
Non CO2 might seem totally opposite from EI, in some ways it is, but they are all defined by the rate of growth.

Putting all these different methods together, finding indirect relationships, looking at it from a very different perspective, this is not some simple thing for aquarist. So be careful of the little sound bites.

See if they can really take it apart and then try to ask these same questions and see if you can answer them yourself, convince yourself.
I do not need convincing.

Read that Tropic article also:

http://www.tropica.com/article.asp?type=aquaristic&id=142

Regards,
Tom barr
 
Do field weeds grow in the established forest?
Or only where's there's a nice opening?

Takes a few years to get the forest really chugging along.
Similarly, aquatic plants ....once they are chugging along and well established, dominate the system, much like a forest.

If you cut the forest down, it takes a long time and a lot of effort to restore it. Likewise, you remove all the aquatic plants, it much hard to restore an aquatic system. Nutrients and CO2 are the same in both cases.

Life history/cycle of weeds/algae are similar to the aquatic plants/trees.
It's a fairly normal thing, not that much mystery. Algae and plants compete, but not much and then mostly for light.

If you destroy the forest, say remove all the nutrients from the soil, will the leaves and trees do well? Not likely, over time some trees will die, some will lose all there leaves the weeds will appear because of gaps in the canopy.

Also, if you suddenly slow the growth of aquatic plants, they normally remove NH4 waste from fish and rotting/dead vegetation, tiny invert critters etc........and the O2 they add to the sediment drops and declines.
There maybe a link between the sediments, roots, bacteria and the algae perhaps. Not sure though.

So there's might be many different chains, cascades, indirect things occurring.

It's not direct, there's little evidence that it is, even in high light aquariums, I still have no algae, however, those tanks are much less stable and have less wiggle room, harder management.

But certainly are possible.

Still, it's generally not a goal for aquarist to have really high rates of growth. So most simply use less light, get away from HLD.

Some insist on high light and then wanna play this game with limiting nutrients to limit growth, which makes things tougher, not easier. Some suggest it helps with coloration this way, but not really, I have not seen it, I still get real nice color with lower light, so does Amano.

Still, the forest analogy works well for some to grasp the idea.
There's the elephant and mouse analogy as well, also a car and an accelerator/gas use.

Regards,
Tom Barr


I think what your saying is lots of plants, LOTS! This creates a situation where the tank has nowhere for the algae to grow.

I have lowered lighting as you suggested and are going to do two water changes a week instead of just one to see how this affects things.

The tank is starting to really fill out. The algae outbreak I had is really dying off now.

Lighting I had was,

2 slim T-5 Coralife twin fixtures

1 10,000K 21 watt
2 6,500K 21 watt
1 6,500K HO 39 watt

I took out the HO and replaced with a 21 watt 6,500K lamp bringing me down to 1.8 watts per gallon from 2.2. I’m also slightly lowering the photo period from 14 hours to 12.

Let’s see what happens.

Newest picture,

full003.jpg


I wish I had a better camera, might be time to buy one.
 
Last edited:
So as the plants take off, you notice, less algae?

You should, this is a general observation that is universal, same is true for natural systems.

So before, you often still have the same ppm's, maybe you now have even more?

But no algae, so what in terms of the plants, is really different?
Does good plant growth just happen instantly? Or does it takes a say 1-3 weeks to get going after you make a change? Most nutrient responses tend to take about 2-3 weeks for the full effect to be seen for aquatic weeds.

CO2 as well, light, about the same also.

It takes some time for the plants to build all the biochemical enzymes required to maintain and keep a steady rapid growth rate.

If you bob between non limiting and limiting levels during this time frame, the plant really cannot get going fully.

Micro_Growth_Curve_Use.jpg


If you bounce between C, B and A, then the enzymes have a tough time working at peak efficiency. If you stick range D, then you have the widest range to work with, the easiest target to hit, and the plants can run the biochemical pathways at a high rate.

So even with little light, they can spend all their resources getting the light, rather than trying to deal with N or P limitations.

This hurts the plants much more than the algae when you limit nutrients.
Plants take longer to get all their biochem machinery going, but once they do, they really take off.

The idea of resource allocation is powerful here.
Should the plant allocate resources to trying the scrape every little bit of the N, P, Fe, K, or worse, every bit of the scant CO2? Or spend it on getting every last photon of light?

This requires the least amount of energy and the least amount of effort by the plant. So this seems to be a sustainable approach in those two terms.
It's also easy for aquarist to manage. So it would seem like the best option.

As plants grow, the algae that colonized a leaf will now be well shaded, so plants actually out grow their algae epiphytes and simply do not worry about it growing on them, since once they get near the surface, they will block all the light for algae. We prune, so the plants do not make it, but keep a nice clean tip.

A few rounds and the entire trimmed plant is spic and span clean.
Plant growth and uptake are both moving targets, they change a fair amount with time, I have 2x the biomass in say 2-4 weeks time.
This is a lot! But in general, more plants = better.

I am not trying to sell you on any of this, just what makes the most sense, what has the support of the basics in aquatic biology and plant science. You should look stuff up, read more etc.

Test and try this stuff first, then see what you think.
This will get going and be more successful with plants, then you can always go back later and test more curious academic questions etc at your leisure.

Folks need to prove this stuff to themselves.
No amount of me or anyone else heehawing will be as effective as that which one sees with thine own eyes.

You might also search the Dry Start Method, this gets things going really well without any labor or water changes etc. I advocated this some years ago, works well with all methods.

http://www.plantedtank.net/forums/g...ion/52332-new-method-start-up-algae-free.html

This established plants, cuts way down and initial plant cost etc.......takes patience though:swear:

Many do not have that, but are very amused at how well it works and start liking terrariums when they have a thick rug of nice HC all over.

Regards,
Tom Barr
 
Cracking me up Tom but very nicely put. Good science with a folksy tone to the whole thing :-)

Using this methodology I've manage to figure out a system for growing in the GH without using a single chemical spray. Only beneficial insects and a mycobacterium. The hardest part is keeping my crew from pruning the plants. They want a neat and pretty GH with orderly rows. I let it turn into a tangled jungle and only prune very little. The hardest part is learning how to do it the first time. It just takes time, error, more error, and more error until you finally figure out how.

I'm just starting to really get this aquatic plant thing down. Got my first algae "free" tank going right now. BTW I was just thinking of doing your HC trick on my little 3 gallon tank at work. I just have to find some good quality HC to start with.
 
The tropica article was most enlightening; I had never before understood or appreciated the fact that a plant expends energy in consuming what it needs. The experiments with light and C02 really proved that remedying one limitation also helped ammeliorate the effects of the other by freeing up more energy for its utilization. Also noted the importance of allowing time for plants to modify enzyme production when adjusting to changing conditions.
In my own tank I now have Eco-Complete after 3 1/2 yrs of Aquasoil, and am slowly realizing that the conditions which formerly produced good growth despite no measurable P or N may no longer apply. And even though I only had DIY CO2 at the time, perhaps the plants were utilizing it better then because they used less energy absorbing nutrients from the soil rather than the water.
The energy concept should help me understand things a little bit more now. Thanks.
 
The tropica article was most enlightening; I had never before understood or appreciated the fact that a plant expends energy in consuming what it needs. The experiments with light and C02 really proved that remedying one limitation also helped ammeliorate the effects of the other by freeing up more energy for its utilization. Also noted the importance of allowing time for plants to modify enzyme production when adjusting to changing conditions.
In my own tank I now have Eco-Complete after 3 1/2 yrs of Aquasoil, and am slowly realizing that the conditions which formerly produced good growth despite no measurable P or N may no longer apply. And even though I only had DIY CO2 at the time, perhaps the plants were utilizing it better then because they used less energy absorbing nutrients from the soil rather than the water.
The energy concept should help me understand things a little bit more now. Thanks.

No, it's due to the fact that you had less total nutrients, not water column vs sediment.

Plants do not care(pretty much all plants, even land plants), as long as they have enough from either location or both. Plants, aquatics and other wise, are opportunist. They will take nutrients from either location, but.........you cannot measure it if the nutrients are in the sediments, not the water column.

If you add them to the water column, at least you can measure them.
You can measure them in the soil, but few hobbyist do this or even bother.

A good paper is from Tom Madsen and Nina Cedergreen(2002) on this topic or water column vs sediment. They cut off the roots of 4 aquatic submersed weeds, they have the same rate of growth when the water column was rich as well as the sediment same rate even with roots or without.

It's a big mistake to think plants prefer one over the other, they will go after any location, but the bottom line is the total nutrients must be the same/non limiting. Location is much less important.

So it's easier for us to use sediments, once added, long term.........and a little bit of water column dosing as well, they complement eachother and allow more wiggle room for each method of adding nutrients over time.

Regards,
Tom Barr
 
AquariaCentral.com