I've seen this movie before (he he he). In The Matrix Morpheus says to Neo; I can only lead you to the door. You must walk through.
Think about this for a second; why does dosing Excel make so much of a difference? If the plants were assimilating 30 ppm CO2 prior to it's application they would be CO2 unlimited and addition of Excel would not result in much improvement. If you can see a dramatic improvement upon the addition of Excel that must mean that your CO2 injection was inadequate, mustn't it?
Barr estimates that 90% of algae problems are CO2 related. This 90% is comprised mostly of people who "just know their CO2 is good".
Matt, I'll plead with you to just try turning that needle valve some more. Slowly push it to max your fish can endure and leave it there for a few weeks. Then observe and report. I'll wager a beer that you'll start to kick that BBA in the bum.
Yes, remember it contains that chemical in the same family as formaldehyde, glutaraldehyde? That kills the algae that is there, but the part of the glutaraldehyde what makes the plants grow better is the carbon part (C5H8O2). I'm guessing that somehow the carbon is stripped by the plants and the remainder is just H and O, so essentially water. What I'm getting at is that if the plants were already getting enough carbon from the injected gas they would not pull as much carbon from Excel. Apart from the biocidal properties the carbon feeds the plants. Don't you normally see that the plants perk up after a few days when you use Excel? Well it's the carbon that they strip which then enables them to uptake more NPK and traces. If they were already saturated with max levels of carbon from the gas you're adding they would not strip the Excel of it's carbon as much and you would not notice that much of an improvement in the plants' appearance.
The amount of improvement in the appearance of your plants when you add Excel is therefore directly related (and probably proportional) to the degree of carbon starvation being experience by the plant when Excel is not present.
understand what your saying Clive, but I really can guarantee that my co2 is high.. but yet it still survives.
I find it hard to believe that having adequate co2 in the tank would KILL it, as all plant life utilises co2 to survive, so why would BBA be any different? CO2 cannot be damaging to plant-life while held in solution.
Normally, low co2 causes algae of varying types because the biomass is struggling to grow, therefore providing the algae with everything it needs with no competition. My biomass is growing like nuts! Yet the BBA still competes with it.
It has to be something else. We must be missing something.
There are many things about plant husbandry that are counterintuitive. I suppose that's why there are so many disagreements. Sometimes the truth appears incongruous. Remember when most people on the planet believed that nutrients cause algae? It seemed obvious and when it was suggested that the opposite is true it was very difficult for me and most people to accept because I just knew nutrients caused algae. I could see it in the tank, so I understand your conviction totally, believe me. The thing is that I also understand that it's easy to gas your fish and to still have a carbon deficiency. I've been there and done it. I reviewed what I posted and I noted the various ways that CO2 can be poor. The fact is that the distribution of CO2 in a tank is not homogeneous so that as a result of flow patterns there is an uneven distribution. One could easily have a high concentration area right next to low concentration area. We have no real way to determine the concentration profile. Additionally, as the plants grow the distribution profile changes further complicating the issue. It's really a jigsaw puzzle trying to balance injection rates and flow patterns.
I'm always questioning the things that I think I know. I have similar problems in that some plants rot in some locations and are fine in other locations. It could be that the ones that rot were just weak. I'm dosing adequate nutrients so the only thing left on the checklist is light and CO2.
On the issue of the Excel, check the post again. What I said was that the plants are using the carbon portion of the glutaraldehyde which the algae have no access to. The algae are negatively affected by the entire molecule since they are not able to process and reduce it. Glutaraldehyde as far as I can tell is basically a disinfectant. From what I gather it's used in hospitals to sterilize operating instruments. At certain levels it becomes toxic even to higher plants but at low levels it can be processed and used by the higher plants.
You are correct in that I don't know the entire content and formula of Excel. Only Seachem knows that so we are forced to make assumptions which may not be accurate. I feel fairly confident though that iron does not have any algaecide properties.
In any case, as I tried to point out CO2 is more than about mere ppm but is about what ppm is reaching and being assimilated by the individual plant. Since it is the most ethereal of all the nutrients it requires much more effort and applied science than any other aspect of plant husbandry and should not be so easily dismissed.
This isn't a disagreement. you are insisting you are right when you know nothing about the other tanks in question and you call into question the ability of the tank owners to assess their own tanks.
I for one may not be highly experienced in planted tanks but Zig is and I would take his word over yours anytime.
I will get banned for this post but so what.
I'm sick of reading your full page essays copied out of books and other websites.
You dont discuss or debate. you insist you are right hence responding to me with 'whatever you say Andy'. I consider this an arrogant as well as dismissive gesture from someone who bores everybody to tears with his page long plagurisms.
You say 'I'm always questioning the things that I think I know'????
I bet you always come out with the right answer, after asking someone else what it is.
Opinionated is often an overused word but it definately applies to you.
I respect Tomn Barr and I would go as far as to say I admire his passion for what he does. He definately knows his stuff and I have taken much advice from his posts and virtually always benefited from them. I have taken advice from others posts as well but I fall asleep less than half way through yours.
Anyway bye bye UKaps. I think that needed to be said before I left.
Good Luck to the people I admire and respect like JamesC, GF, GE, Them, Zig, Dave, Jimboo and others that I have forgotten and I will see you on TFF where people like CEG are diluted by the many many decent open minded users.
By the way people the apparently 'inappropriate' image link in my signature that was removed earlier was a picture of Leilani, Not naked, not even topless so god knows why someone took offense to this.
Just goes to show how damn serious some people are as administrators.