"Algaebusters", CO2 and Nutrient Limitation, and Going All Out

Here are some somewhat random thoughts about my algae problem that, in the end, connect up and lead me to take certain steps.


1.) I have been too sparing with both CO2 and nutrient provision. I knew of Leibig, but I just haven't been playing this game on the correct scale of intensity. I have been dosing on a kind of PPM regime with testing. If nitrate and phosphate were showing as just barely there, I assumed that the plants were uptaking right down to the wire. Same with Fe (and thus all trace). I also expected CO2 at 30 ppm to be satisfactory.


I've been telling anyone who will listen for some years now that PHOSPHATE DOES NOT CAUSE ALGAE, yet I had a reluctance to "overdose." I have had recurring nuisance algae infestations - very discouraging. I went back and reread all the threads about dosing and algae and light and reabsorbed everything Tom Barr has posted here. When I started gradually, over three days, increasing macros and CO2 and tested every twelve hours, it did not take long to realize that the plants ate the stuff in truly huge quantities. I also am cutting back the light with the view to adding it in later as can be allowed (hopefully I can bring it all back because it's a really nice bright 6300K day in there when it's all aglow). Lots and lots of LEDs.


The plants had seemed to be okay, in good color, and pumping out the O2 pretty well (I monitor O2 saturation %) under the bright light. But the CO2 - Nutrient - Light balance was out of whack. Some newly planted Hygrophila and Ludwigia shot up, but had then seemed to stop "being vigorous", and all my Crypts and swords just decided to stop growing and fairly rapidly collected algae on their leaves (interestingly, the older leaves are more vulnerable).


Rereading those threads, I got up the gumption to go straight at this problem with some real conviction. Now, going into a fresh day with nitrate at least 20 ppm, phosphate around 3 ppm, and iron (all forms) at 1 ppm, and CO2 right at about 60 ppm, I am anxious to see results.


Thus far, none of the many small fish that reside therein have commented on the new conditions.


2.) Tom Barr has used the term "algaebuster" in connection with certain types of hardy plants. For a fact, he used the term in his 2012 AGA Convention address in passing, and when he said it, I wanted to stop him then and there and pump him for more info. Being left to speculate, I will do so - Plants that are aggressive CO2 competitors and grow really fast - i.e. "weeds".


If algae is inhibited by macrophytic growth, then It makes sense that lots of these types of plants in a system WITH ALL LIMITS REMOVED is a good (fast and easy) way to thwart algae. For that matter, I get that this applies to all plants no matter how demanding or exotic, but the "algaebusters" are the tough and hungry weeds. Such as Egeria densa, perhaps, or Hygrophila difformis (Wisteria). Tom, have I got this right? I would appreciate your elaborating on this. Very much.


Speaking as an experienced novice (I have been a newbie for about 12 years), I confess I like weeds because I like the jungle look and it's easily achieved with plants that are not highly demanding (proviso - all the more important to flood the environment with resources for growth).


So, here's a hypothetical proposition that derives from this: You have a high-light high-tech tank that is prone to frequent algae infestation. You suspect "old tank syndrome" so you uproot everything, remove and rinse all the gravel, scrape and scrub all the surfaces - and you trim and attempt to salvage your Echinodorus. Plant great whole bunches of Egeria, Val, and Hygro, turn down the lights and turn up the food. New algae will not come roaring back. Any older places of infestation that eluded removal will eventually die back. Faced with the prospect of harvesting large surpluses of waterweed, you are happy. Is this reasonable?

 

Thanks, Pikez


No, I agree that "slight excess" of nutrients does not cause algae. I think what I found is that, there being no evidence of any surpluses at all, I was actually running a deficiency of nutrients. Same with CO2, 30 ppm was just not enough. All this because the light was too high. What high-tech/high-light is about is that, if you are willing to tolerate maximal plant growth, you unleash all the limiting components except light, which is the easiest to control, up and down. Let the light be the ecosystem's "throttle". Unfetter all other growth factors. I go the high-tech route because I like a brightly lit tank, and that appears to be the most fool-proof way (really the only way?) to avoid algae issues if you want this much light. This is the path I thought I was on but I was just underdoing it. I believed I was providing a slight excess while in fact I was starving the plants.


Oh, yes, I did the breakdown and rebuild already. I have done this pretty much once a year for the eight years I have had this tank. It is a 210 gal with a 24 x 72 footprint. I take a full day and do the whole thing in one go. I like doing this - it feels good to be clean. But it's not the kind of thing I would do more often than that. I don't vacuum, I remove and strain. It needed it. In between, I do as-needed maintenance like clearing out debris, trimming hopelessly infested leaves, scraping surfaces, assuring filters (total combined minimum 1200 GPH) are running up to speed and clear of filtrant. Plus, a lot of the gravel and detritus get attention when I do the occasional re-scaping and so on. I have always advocated the view that DOCs and their root causes play a roll in algae and I am pretty assiduous about maintenance. This was one reason I have been looking for other explanations for my algae problem.

 

Exactly. The object lesson here being "If you are too timid about it, you will probably come up short." When you establish a method, trust in it, or do something different.


Still would like to see Tom expound on "algaebusters"! Something else that comes from paying close attention to Tom Barr's passing comments: is there a plan for when we might see THE BOOK? It's sorely needed.

 

Well, yes, I am adding more plant mass and I think that's a start in the right direction - and in keeping with the theory of the algae-suppression aspect, I am sticking with fast growing, hardy stuff. So this needs to be properly fed. I have a considerable amount of Hygro and Ludwigia already, but was getting poor growth after a time and then the algae came on. Step one was to cut down on the light. Step two was to increase the CO2.


I have a grip on the principles of the method alright. I have been using the PPS method of nutrient supply and just plain under-dosing. Thought for a while it was enough because testing always showed small amounts present. I need to emphasize "small". Which is why I went "all out" and started piling it on. The plants are hungry. Large amounts of everything are disappearing into the system. EI with a PMDD routine, as suggested by Tom in a sticky, I think will suit me.


I am proceeding in the confidence that it's the thriving biomass that will stop the algae.

 

Sure, Pikez, I would think in a given instance where any or all plants are thriving are suppressing algae, but I would also think that starting from a given set of conditions, the theory which supports this should predict that fostering weeds gives the advantage. In any case, the context when Tom used this term seemed to me to suggest that he meant a specific category or type.


Tom answers the allelopathy arguments in previous threads. The exact manner that algae is suppressed by plants doing well I think has a biochemical component, but may be mediated by bacterial activity. I am suspicious of claims that secretions into the water column diffuse all over the tank and adversely affect algae, since these would be organic substances subject to chemical filtration adsorption, but I am open to arguments based on EMPIRICAL DATA. Algae establishing directly on the leaf or stem is a different story, of course. The role allelopathy plays in natural environments is also a different story.

 

UPDATE


All the "algaebusters" have overtaken this tank - lots and lots of plant mass. I am holding CO2 well above 40 ppm.


Experimenting with the lights: gradually dialed back the intensity and photoperiod. Spirogyra (the "index") would return more or less at the same rate until a certain threshold was crossed. With the main LED bars set for maximum daytime at 40% capacity and a significant shortening of the daytime, the Spirogyra is drastically slowed, as well as the BBA development on the Echinodorus, etc. It's interesting how the system seems to have just "snapped out of it" as soon as that last reduction was made. This was about two months ago, but I have waited that long to make sure this result is real and durable. Very encouraging so far.


I have arranged a dedicated LED bar set for 100% to be manually switched so I can select high illumination just for observing periods. Rarely is it on as long as three hours at a time; usually an hour or so two or three times a week. So I can have a bright tank when I want it without really opening the throttle.

 

Pictures from today and a year ago. I am pleased that the algae has been very much under control.

 

I have gradually adjusted the LED bars to go to 90%, but had raised them 3" several months back. Raising them that much has proven to be an improvement in discouraging green algal growth on upper leaves. I have not measured the PAR recently. The kH is held around 9 degrees. I use a pH controller and keep the pH at circa 6.6. I will continue to use CO2. I am converting the stuff to biomass at a pretty good clip.

The coverage, however you measure it, is at least 50%. The big sword is very productive and the nymphaea is prolific. There is a lot of shade at this end of the tank. I allow the stem plants to get tall and I only go after them when their tops start blocking light to a significant extent. The pruning shears come out when the daily maximum O2 production starts to drop off a ppm or so, which is about once a week. The whole floor of the tank is densely planted - dare I say crowded. I have duckweed, but it's easy enough to net out most of it, and I suspect it is being useful in the algae battle.

I have previously advocated activated carbon as useful against algae. Last year I stopped using chemical filtration completely, but came quickly to the conclusion that it was a big mistake. I now use BioChermZorb, as I am convinced that BBA and similar algaes like DOCs. I bring your attention to Andy McDowell's article in last Jan-Mar TAG. I advise chem filtration, especially with high bioloads.

You don't need to strain to see some algae in this tank. It is an aquatic environment, after all, and I have a LOT of fish. But I have not been plagued by nuisance infestations for over a year now. So this robust jungle weed thing seems to be working out for me.

Thanks for the likes. I'll put in some more pics shortly. And thanks, Tom, for the reply.