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· Plant Whisperer
2,547 Posts
One of the biggest problems folks had were based on old myths about the dangers of excess ferts when I suggested this in the 1990's.
I thought those ideas were correct myself, but then noticed they could not be.
This is partially true.

Macro ferts have much higher toxicity levels than micro ferts do. Heavy metals are many times more toxic and have fairly low toxicity ranges, some like copper well below 1 ppm (0.15 ppm actually). Long term exposure to heavy metals makes the toxic concentration lower.

· Plant Whisperer
2,547 Posts
I'm sure you could dose enough, but it would REQIURE gross error, massively so, on part of the aquarist, I've never once seen this in some 15+ years of experience of helping folks on line.
Not as high as you'd think depending on the micro we are talking about.

I've dosed 100-200X what I am suppose to, dosing pump dose it all at once because I did not set the switch on the pump correctly. No death, but a nice yellow red color in the tank. that was with SeaChem Flourish and TMG. Maybe CMS will?

No one has show that to be the case yet, so for macros and micros, you need to get 10X or more dosing errors before you see risk which is a wide wide error range.
Two things,
Flourish is quite dilute, so 200x a normal dose isn't that high of a concentration. CSM+B is much more concentrated being in dry form so I'd expect that to be more likely to cause an overdose. Compared with a 200x overdose on CSM+B which would almost certainly ruin a tank.

When you dose a concentration a given nutrient the short term effects of a toxicity are not seen unless the concentration is very high. That is why ~1 ppm copper is considered "toxic" to algae and plants for a short term exposure (1-3 days). If you increase the exposure time to a few weeks copper becomes toxic at 0.15 ppm, possibly even lower, to many plants. The recommended dose for copper is below 0.02 ppm to avoid any sort of inhibitory effect.

Partially true?
Please support such statements.
I've had these same discussions for nearly 20 years perhaps 100 times now.
I can ask the same question of you. Please support your statements with actual scientific background literature. It is very easy to refute another person's argument, but much harder to support your own with published long term study evidence, or peer-reviewed literature based arguments.

My work-in-progress literature research into toxicity ranges (mainly for unchelated micros):

I am fairly certain you have already read the CSM+B iron toxicity thread where I provided background research and thought on the matter but here it is again so you don't have to search for it:

Shrimp, fish die for many reasons, even without plants and such.......we have to exclude those possibilities prior. If we have a case where they have not died and done well in spite of the high dosing of Traces........well, that falsifies the claims.
The effects of certain concentrations of nutrients on shrimp and fish have been extensively studied and there are very well documented LD50 values for that. Copper is one of those that has been looked at very thoroughly. So when you say we have to exclude those possibilities when trying to figure out if high traces makes a difference I disagree. It is very relevant. If we are reaching known values for toxicity or even approaching a fraction of those values then we are entering dangerous territory.

Furthermore, there is no need to overdose micros (except possibly iron), plants simply don't use that much of them. Have you ever seen a molybdenum deficiency? A copper deficiency, manganese? Do you know that many researchers actually have difficulty keeping their sample water pure enough to actually demonstrate a deficiency of many of these micro nutrients? What benefit do we get from massively overdosing traces when we know - from hundreds of studies - that heavy metals can and are toxic to fish, shrimp, plants, bacteria etc at very low concentrations...?

Now if we cannot dose say 10X the suggested amount, then we cannot say it's the trace, but perhaps likely it is, but we cannot rule other basic aquarium causes either.
Many studies I have read also talk about ED05 or ED10. Basically the dose that it takes to negatively affect 5% or 10% of the plants. Do you think we can easily see toxic effects on plants if they are at the lower end? Affecting only 5-10% of the plants? Does that make the toxic effects on our tank inhabitants any less concerning if we are aiming for unlimited healthy growth?

Again, I see no point overdosing micros when 99% of the time you'll never get a micro deficiency even with very low concentrations. On the other hand toxicity is a very real possibility and there are documented literature values where researchers have exhaustively tested and found low concentration effects.

What about people who have naturally higher levels of certain micro nutrients in their tap water? What happens when we add very high trace nutrients to their tank? Both doses combine and you can fully enter toxic ranges.

What about people who have small tanks and accidentally add a teaspoon of micros 3x a week? A teaspoon doesn't seem like that much to a beginner, but in a small tank it can quickly reach toxicity levels especially since plants don't use up micros as quickly as they do macros.

When you say a specific hypothesis, liek traces kills things, cause algae, are best off stating a specific ppm etc, say

"0.2 ppm Cu from CMS+B will kill 50% CRS if you dose this amount daily for 4 weeks."
I never said they cause algae. I said they damage plants when micros reach certain ranges.

· Plant Whisperer
2,547 Posts
Tom, you have not addressed several of my points in your last reply, nor have you provided any links or journals which support your conclusions that micros don't build up to toxic ranges in the aquarium. If you want to talk about proof then you need to back up your claims as well. You mentioned your 15+ years aquarium experience in an earlier post. That is not proof. I also have 15+ years of experience, as well as many years working in research labs, Yale University being one of them.


0.5 Fe
0.01 Cu

Say you want 0.2ppm of Cu at your threshold:

0.5 Fe x 20X = 10 ppm
0.01 Cu X 20X = 0.2 ppm

Overdoing it 20X is not been done by anyone I've known or seen on line ever.

Say the toxic dose is 0.02 ppm Cu
That's still 2X the more than the upper limit for EI.

Math don't lie.
If you are starting with pure RO water with no other sources of micros then you are correct. However, most people do not reconstitute RO water, they use city or well water which have varying quantities of micro nutrients in them. I do not claim that copper is the heavy metal that always causes toxicity problems in our tanks. Most of the micros can cause issues when in toxic ranges. There are many situations that can bring about higher than normal concentrations of one or many micro nutrients. I already stated two in my previous post:

Zapins said:
What about people who have naturally higher levels of certain micro nutrients in their tap water? What happens when we add very high trace nutrients to their tank? Both doses combine and you can fully enter toxic ranges.

What about people who have small tanks and accidentally add a teaspoon of micros 3x a week? A teaspoon doesn't seem like that much to a beginner, but in a small tank it can quickly reach toxicity levels especially since plants don't use up micros as quickly as they do macros.
I have seen these both happen and have documented water values for each micro nutrient that was in the water at the time. In each case micro nutrients had entered the toxic range and unsurprisingly the plants showed micro nutrient toxicity symptoms. In addition, when micros were flushed out of the tank using RO water the problems disappeared as well.

Yet another example is when soil is used and heavy handed EI dosing is continued. The combined micros leaching from the soil and from EI can easily reach toxicity ranges.

Have you tested copper in planted tanks? It does not last long. Try it and see for yourself, do not take my word for it. Plants can handle quite a bit. Shrimp are the best bet for a hyper sensitive species. They are the best bet for a "canary in the coal mine"
I have actually. I had my water samples analyzed by lab grade equipment several times and there seems to be a lot of interesting data showing which micros end up staying in the water column. The most consistent part is that plants show signs of toxicity every time the heavy metals exceed certain concentrations. Read the second thread I provided in post #20. In addition to that thread, there are several other threads on various forums that describe similar examples.

See the table of test results when CSM+B was used:

I've shown there's no risk at high CMS+B dosing for Shrimp.
I've got video, I've got long term photo journals, I've got dozens of local hobbyists who have seen my tanks in person.
Those are the facts.
It is good that you are documenting your tests. However, showing that shrimp do not die when CSM+B is dosed in moderation is not what I am claiming. If your copper levels reach the proven LD50 levels for copper or other heavy metals the shrimp will likely die. It is in the literature, or are you arguing that the literature values do not apply in our tanks?

You cannot logically conclude that there is risk, when others have show otherwise. People make these claims X is caused by Y, but then do not test their own hypotheses. These are not my hypotheses. They are yours, you argue for them, then you do the work.
Tom, you clearly didn't read through the links I provided where I showed the potential risk.

In addition, you have not provided any evidence in this thread to show that there is no risk.

Even if there might be and you want to use belief, you can still switch to a different brand. Both management issues are easily met.
Hobbyists test all kinds of things in their tanks every day arriving at all sorts of conclusions, what makes them wrong and you right? You have not provided any links to your relevant toxicity tests, your means of analyzing results, or even background literature evidence as I have when writing replies. There is no way to fact check your statement that 'we can never realistically reach micro toxicity ranges in our aquariums.' You asked for proof of my ideas, and I provided links to some of my research, now where is your evidence for your claims?

Chelation makes a massive difference in toxicity, and we all add chelated metals for traces. I am also unaware of any shrimp studies that had planted tanks, CO2 enriched systems, this makes growth, uptake and many other issues very different compared to the research.
Chelation does reduce toxicity, sometimes by quite a lot depending on the metal we are talking about. I have been very careful to state this in several of my previous posts and summaries.

Research is a good starting point, but unless it's pretty specific to our systems and there's also observations that are not falsified already, it can be misapplied. We assumed that PO4 above 0.2ppm induced algae based on that same logic and research for support.
Research is the most valid way we have of examining the processes that occur in our tanks. Most of the studies I have looked at on toxicities use the aquatic plant species we often keep, there is no closer analog to our system than that or do you believe that your personal tests are more accurate than peer reviewed lab tests conducted by a team of researchers with funding?

Clearly that was not true. The same logic I used there I'm using here. All I have to do is falsify it. If I or others cannot, then I tentatively accept it.
I've already falsified your claim way beyond the typical dosing routines and errors newbies and folks who are prone to make mistakes might do.
CMS might be more toxic to livestock than Flourish, but........I've gone overboard with both enough to know there's little associated risk.
One calculation hardly constitutes falsifying all my evidence especially when I have made it easy for you to examine my data and my ideas by providing links, research journals and data from research publications. You also have not addressed all of the points I brought up in my previous post.

If you wish to do more research and post your findings then I will look them over and perhaps we can mutually agree on what ranges are realistically toxic for each micro nutrient, otherwise as you have stated yourself in several places you do not know what the toxicity ranges are for the micros.

· Plant Whisperer
2,547 Posts
I think both would agree that dosing excess nutrients without water changes or compounding that problem by dosing incorrectly (tablespoons instead of teaspoons) would lead to toxic levels of anything.

Why argue over whether toxic nutrient levels can exist, they can. Water changes and proper dosing can prevent all of this. The problem lies in the sentence preceding this one. Every hobbyist makes mistakes. Yes, they may be huge mistakes by our standards but the possibility still exists.
I think we do both agree that toxicities can occur, but what I do not understand is what is the problem with using the literature values we already have on the topic (which I have looked up already) to figure out where the toxicity range should be and then do a few tests of our own to confirm the range?

What is the toxic level for trace element X in aquatic plants? Beyond a few papers on copper, nitrates, zinc and a few others I have no idea. It would be nice to know, as well as what to look for just in case. I'm like every other hobbyist. I'm human and prone to error.
I've collected about 150 papers so far on various nutrients and the toxicity ranges for certain plants. There is no one toxic value for each of the micros that will hurt every species of plant we keep in all situations, but there are certainly ranges which should be avoided in order to keep our plants safe.

I believe we should take the lowest literature toxic value and then ensure that we do not dose anywhere close to that value. In medicine when a drug is brought to market usually it is required to have a toxic concentration at least 10-100x above the effective dose concentration. So using the copper example, if we were to say that 0.15 ppm is the lower toxic range, then do not dose more than 0.015 ppm to be in the safe zone.

What can we do to prevent toxicity? Dose appropriately and perform water changes. Sorry to derail any debates. But I'm more interested in managing nutrients to prevent both limits and toxicity in the first place. To put it bluntly you are both correct. You just need to move towards the middle a tad more. I respect both of you tremendously but that's what I see here.
Nutrient management is definitely an important part of growing aquatic plants. I use and love the EI method above all others, the idea of abundance rather than nutrient limitation is a good one especially when it comes to macro nutrients. My only issue with the system is the potential for overdosing micro nutrients exists given certain circumstances. Micros are far more toxic than any of the macros and so they need to be addressed properly.
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