So, why does New School = no algae?

It seems to me the answer is far simpler than most of the postulates in this thread. photosynthetic organisms need four things, basically:
water
nutrients(NPK-SFeMgCa-various micros)
a carbon source
light

In an aquarium we control all of these to some degree. Both EI and PPS are about creating a situation in which the light is the limiting factor. Any limiting factor other than light leads to the much faster adjusting algaes capitalizing on the excess light, and what is deficient determines what algaes will persist. Higher plants will monopolize the light so long as their other needs are met, leaving any algaes to starve.

The reason I rule out allelopathy is fairly simple. If the reason were allelopathy, then not only would the algae disappear but we would also see a single plant species completely overtaking the system. Occasionally this may happen, but for the most part planted aquariums grow multiple species in a single tank with only minor competition starvation issues. True allelopathy leads to single species dominance(like what is seen in sunflower fields, oak stands, eucalyptus stands, walnut stands....) This isn't the case in the majority of tanks, so allelopathic action is generally not the case.

Occam's razor is your friend.

DeChaoOrdo said:

It seems to me the answer is far simpler than most of the postulates in this thread. photosynthetic organisms need four things, basically:
water
nutrients(NPK-SFeMgCa-various micros)
a carbon source
light

In an aquarium we control all of these to some degree. Both EI and PPS are about creating a situation in which the light is the limiting factor. Any limiting factor other than light leads to the much faster adjusting algaes capitalizing on the excess light, and what is deficient determines what algaes will persist. Higher plants will monopolize the light so long as their other needs are met, leaving any algaes to starve.

The reason I rule out allelopathy is fairly simple. If the reason were allelopathy, then not only would the algae disappear but we would also see a single plant species completely overtaking the system. Occasionally this may happen, but for the most part planted aquariums grow multiple species in a single tank with only minor competition starvation issues. True allelopathy leads to single species dominance(like what is seen in sunflower fields, oak stands, eucalyptus stands, walnut stands....) This isn't the case in the majority of tanks, so allelopathic action is generally not the case.

Occam's razor is your friend.

Click to expand...

It's usually our intervention (pruning, harvesting) that prevents a succession of dominant plants. I was just looking about week ago at a 120 gallon tank that had turned into a solid green block of Italian val.

Floaters and bryophytes (mosses, hornworts, crystalworts, etc.) are prone to taking over too. We tend to keep those out, or severely control and harvest those in a planted tank. I set up a planted tank at my daughters house. Basically it is now nothing but small duckweed on top and the rest solid with Chara cf. contraria. I suspect many of us skipped or forgot that early phase in aquatic plant keeping when we assumed that plants would all get along. She just now caught on and is starting to regularly pull out the excess Chara and duckweed.

I used to keep large tanks of marine plants, some true vascular plants, most macroalgae. I would start out with over forty different species of sea plants in a tank. No matter how much manipulation I tried, a handful of species or less would dominate and many would vanish or seem to for a while.

rhodophyta said:

It's usually our intervention (pruning, harvesting) that prevents a succession of dominant plants. I was just looking about week ago at a 120 gallon tank that had turned into a solid green block of Italian val.

Floaters and bryophytes (mosses, hornworts, crystalworts, etc.) are prone to taking over too. We tend to keep those out, or severely control and harvest those in a planted tank. I set up a planted tank at my daughters house. Basically it is now nothing but small duckweed on top and the rest solid with Chara cf. contraria. I suspect many of us skipped or forgot that early phase in aquatic plant keeping when we assumed that plants would all get along. She just now caught on and is starting to regularly pull out the excess Chara and duckweed.

I used to keep large tanks of marine plants, some true vascular plants, most macroalgae. I would start out with over forty different species of sea plants in a tank. No matter how much manipulation I tried, a handful of species or less would dominate and many would vanish or seem to for a while.

Click to expand...

Some species definitely are stronger competitors than others, but if allelopathy was playing a significant role results in freshwater tanks would be more like what you described for your marine aquaria. Certainly there is some degree of allelopathic interaction, I simply am saying it seems doubtful that it would be the primary reason for algae disappearing in well planted tanks with sufficient CO2 and nutrient dosing. Floaters in particular have strong competitive advantages since they are closest to the light source and exposed to much higher levels of CO2 than is plausible in the water column. Bryophytes and vals are better adjusted to the low light levels we keep in aquariums(even most "high light" tanks have significantly lower light levels than what would be considered moderate or low light.)

I liked the last two quotes in that article. Real scientists as it looks, not some internet stars.

Regular maintenance, balance - ok. But here's another thing: I've had tanks which where so stable that even letting them evaporate 30% (months without any maintenance) did not lead to any algae growth. Plants do not die. Actually some plants really explode in growth at times - maybe a seasonal thing, maybe accumulation of certain elements. You can refill the tank whenever you feel like it and nothing changes. No algae, no disbalances. If I remember correctly there where also periods when the lights were on/off on a funky schedule because the timers got messed up after power outages. My point is - here's an indestructible tank that does not develop algae despite many basic things being way off.

I have no idea how such extremely stable tank can be intentionally made to happen. The only thing I can think of is that all of these tanks (I've had 3 or 4 like that due to my natural laziness I guess) had a long time to develop. One of these tanks started as just water and gravel (no CO2, very low flow, and not even light!). There where a few fish and there were a few Amano shimp from the beginning. I never planted plants in it - they grew up from seeds in the substrate (was taken from an old tank) I guess and about a year later the tank was full of plants to where there was little room for the fish to swim. There where mosses and some kind of Hygrophila. Also the new plants sprouted for the first time only when the seasons changed - one morning I realized that the tank actually got light - a 1 or 2 hours of sunlight when the sun was raising only.

In these extra stable tanks algae could not live even for a few hours. I've seen BBA completely disappear within 6-8 hours if introduced into such a tank. It just evaporates - maybe it gets really weak and the shrimp eat it. Except 15-20 Amanos cannot take care of every single BBA dot there is in 6-8 hours. It's almost like BBA melts away into the nothing. What caused that? Certainly not low N and P, certainly not low organics. The extra Oxygen that the filter pipe introduces when it discharges 20 cm. above the evaporated tank?

There is something to be said about letting the tank develop naturally. By constantly doing something in the tank we disrupt certain natural processes, some kind of trends. That is especially true if the tank is high speed - lots of light, CO2, nutrients - and if you don't really know what you are doing. A few years ago here on APC I described a way to start a planted tank that employed the idea of very gradual addition of fertilizers - daily amounts which where dictated by the plants themselves. I called it "SubZero" because you could never test the fertilizers with common test kits but if you added them every day you knew they were there. The main point of that approach was to interfere with the natural processes in the tank as little as reasonably possible. By using SubZero you actually end up ramping up the plant's metabolism to a level where you can add considerable amounts of ferts but a few hours after that nothing is left in the water. I have had two algae appearances with that approach (Staghorn and Cladophora) and in both cases stopping the fert additions and two 30% water changes later (over 3 days) got rid of the algae immediately. The Staghorn may disappear easily but the Clado is a different thing. Yet it did disappear completely in 3 days. I used to believe that what was happening was that the tank was forcefully made completely void of macros and micros but now I know I do not know anything.

Ardjuna,

I reread your algae article a few times because it brings up a lot of good points from different directions which is not common for the planted tank forums around here. Below are two things that you may find interesting:

1. One view is that algae is like a disease and show up as result of stress (bad light, temperature...). You don't know but I am the inventor of the algae-erasing pen using fiberoptic cable to direct UV light at algae and spot burn them from a close distance. After hating algae for may years I realized a simple thing - seeing algae as enemies doesn't have to be so. Look at algae as ancient organisms that have learned to adapt in all kinds of crazy situations. They are way more amazing than any fake digital creature that a billion dollar entertainment outfit can put in front of your eyes. In a way - look at them with respect. That funny mind exercise may help you to look at the tank in a different, broader way. It is not about exterminating, overpowering, and not even about outcompeting. It is about understanding. No wonder we usually fear things we do not understand and fear is often associated with aggression.

2. So I had these few strangely stable tanks which I really cannot describe. I was thinking about them after I wrote my post above. It is indeed strange to have a system that is so stable. Certainly in Nature there is no such extreme resilience and stability. In Nature everyting always changes - high water or drought bring a very different dynamic to the body of water. How is it that I had such unnaturaly stable tanks? I have no answer to that but I think we can look at that like this: An aquarium is an isolated system. At least much more isolated than Nature. So in that system it it possible to have extremes in either direction. There are not very many safety nets, buffers, insurances either way. Extreme instability and extreme stability can happen indeed. Sort of like an antisocial, isolated person. If that is so then we can say that the the average planted tank is one that is more toward the unstable state. There are plenty of posts about people going on vacation and "shutting down" or "slowing down" the tank because without constant care it deteriorates. Deterioration is expected in "New School of Planted Tank"! Tanks that "run slower" (lower light, no CO2, etc) seem to be more toward the stable state.

The title of this thread is misleading. Reduced algae are not a result of some "New School" of higher aquarium education in which just 4 things matter (CO2, ferts, light, and water changes). "New School" is about the effort that you put to force the system in a state we call "clean". Read item 1 above again.

And here's some more about item 2 above: There are enough people that will show pictures of tanks run using EI or PPS that are both "clean" AND stable. Just a few EI fans can show such pictures and there is always the same common thing - these tanks are always old and well established. An old tank is a completely different animal than a new tank (6-12 months old). So you can start your way to stability by forcing things to be your way, then at some point the tank gets established and you certainly attribute that to everything you did. But the truth is you can arrive to that established stable stable state by not doing anything at all - just leave the tank develop with very low light, no or very few fish, and no or very little CO2. So it turns out that both "Old School" and "New School" achieve the same thing. Except we will all agree which approach leads to much more risk of all kinds of issues along the way. Drop the ball once and both EI and PPS will bring algae quickly. EI can do that literally overnight because of the ultra high concentrations of chemicals floating free in the water, excess light, and excess CO2 which suffocates the biofilter among other bad things. The cure for any problems with EI or PPS is more of the same - more water changes, more ferts, more CO2. More one of 4 things, more effort, more aggression.

I may start a new thread - "Why fast food is so tasty, cheap, and satisfies both my hunger and my mind?" I see quite a few parallels with the mentality of many planted tank folk. As an old rock-n-roll song goes "You want it - we got it!":

Left for three days. Dosing pump malfunctioned and delivered 1.5 liters of macro solution at once instead of ten ml/day. I came home to a cesspool of brown filamentous algae that waves in the current like the hair of a mermaid. If I were competing for the best algae crop, I would win. Green algea covered the glass.

I already have excessive flow, so it's not that. Lighting is high (80-90 PAR at substrate in center of 90-P) but CO2 is on a controller set to 6.2 (highest after lights out 7.0-7.2, as it varies) that starts an hour before lights on. 8 hour photoperiod This is not a new tank; these are not simply diatoms, and I did a large water change (at least 90% of display tank)) before I left, anyway. My filter is oversized for my tank, loaded with biomedia, and cleaned a week ago, anyway. I don't even have any fish so there is next to no visible detritus. I quickly planted some legandara before I left. I find it extremely hard to believe that the minute amount of disturbance to the substrate bed had any effect. The macronutrient overdose obviously caused this. It is a "should I just start over?" situation.

If five months worth of macros, all dosed all at once, with 5 ml/day of double-strength E.I. micro solution, a full point pH drop with co2 kicking on an hour before the photoperiod (which I would bet my life would kill any shrimp I tried to keep), is not non-limiting, then I don't know what is.

I have read time and time again a particular Dr. say things along the lines of "if excess x, y, or z nutrient could trigger an algae bloom, then any hobbyist could experiment and add excessive amounts to induce algae. But this does not happen." or "Eutrophication in natural bodies of water is not induced by phosphate/nitrate" "Phosphate does not induce algae" etc. etc.

Well, it happened. It was induced. I have never had anything but unfortunate luck anytime I do anything that has anything to do with a particular Dr.'s method in any way. When I'm not suffocating/poisoning my fish/shrimp, I'm dealing with algae at the best of times (which couldn't possibly be caused by excessive nutrients, or so some would have you think....) or coming home to an expensive cesspool. And this is when following it to the LETTER and going above and beyond measures of cleanliness and maintenance. Do not tell me I need more CO2, which is some people's answer to anything and everything. Don't tell me I need more plants. I had like 70% vegetation coverage and the tank was immaculate before I left.


Whatever. I'm so over it and over everything that has anything to do with E.I. in any way. I am consistently met with death and decay. And it's not like I am completely incompetent: I have a scientific background, have taken botany classes, four years of chemistry, etc. My tank could be cooler. It gets up to 85F during the day. But I find it funny that, despite the heat, I do not have algae running rampant whenever the autodoser was dosing as programmed, yet when nutrients are overdosed (which, according to some, doesn't even matter as long as they are all non-limiting and micros aren't dosed so high to cause toxicity) I magically come home to a sewer.

I can't help but wonder if it would have been AS bad had I been using a good UV sterilizer. I should also calibrate my pH probe and raise the lights. Regardless, I'm going back to the Brighty series. E.I., when followed religiously, has failed ne time and time againb. Even if the Brighty series is overpriced and diluted, at least I can say the ADA system has always worked for me flawlessly in the past. E.I... not so much. I have often wondered if people who claim to dump so many nutrients in their tank and crank the co2 up so high (I can't keep shrimp alive to save my life! Hundreds of dollars wasted trying over the years! To keep them alive longer than 24 ours would be a miracle despite 3+ hour drip acclimations!!!) and have great results and plants with sparkling cuticles and minimal to no algae with happy livestock are LYING about something.

And as a side-note, those Twinstar devices really do inhibit the growth of algae. But on the disc ONLY. The disc it's self is literally the only surface in the display tank that was spotless and pristine. It was so perfectly clean, I was astounded. Since it only prevents algae from growing on it's own mesh surface, It's astoundingly useless and a complete waste of $150. What a JOKE. I should have known better, anyway. I fell for a gimmick hydrolysis device. Snake oil.


I am a paid subscriber to the Barr Report. Which offers no real benefit by the way. I should really vent my frustrations there.... Sorry for the rant.