I found that I had been making a large error in dosing potassium. I've been dosing roughly 80 ppm per week for about a month or so. Using EI dosing, I don't think I really need to dose much if any K. I'm doing water changes to get levels down.

Something else has been going on that I'm wondering if it is related. My plants have been apparently consuming very large amounts of iron . I dosed .4 ppm two days ago and my Lamotte test shows no measurable iron today 48 hours later. Plants do show signs of iron deficiency. When I dose things improve.

Is it possible that excess K or something else is causing the Fe to precipitate out so that the plants can't use it ? So when I test the Fe levels go down and it appears that the Fe is being used.

The only other thing I could think of is a possible Magnesium deficiency or maybe my plants are addicted to iron.

Henry Hatch

KNO3 typically supplies enough K.
Rarely do you need more.

Fe test kits are well.......essentially worthless.
0.4ppm does not tell you anything that is really useful.
I can have great plants either way.
Main thing is to add some Fe every 2-3 days ina higher light tank, daily if you are really into it, but no less than 2-3 days for high light/CO2 etc.
High K and Fe will not preciptate one another.


Regards,
Tom Barr

If my expensive Lamotte Fe test is useless how about my expensive Lamotte Nitrate and Phosphate test ?

Bingo!! You figured it out!

I'm just not much into testing except for experimenting, so don't mind me.

Let me see if I got this right. My lamotte tests are no good, kh/gh tables are no good, nobody seems to agree on even the most basic aspects of keeping a planted aquarium, most successful planted aquarium keepers seem to have a certain niceness of seeing so that they know what their plants need.

Is it any wonder why this is a niche hobby which may be destined to be populated by people with advanced degrees in biology, chemistry, or mysticism ?


Henry

All kidding aside, I wish I could just watch the plants and fish and know what I should do next. But, I don't. I follow EI as best I can, use the drop checker to be sure I have adequate CO2 in the water, try to get good water circulation in the tank, and, for enjoyment, try to understand more about how an aquatic plant garden grows. The best thing about Tom's efforts is that they seem to all be aimed at making life simpler for all of us, not making it more complicated.

My particular weakness (I think) is that I am too lazy to do as much cleaning of the tank as I should do. I would like to say I am getting much better at that, but if I said that I would be telling a little white lie.

And, my aversion to testing is based largely on laziness, but I welcome the fact that doing all of that testing seems to largely be unproductive anyway.

Hey, its a hobby, not a job!!

So you shouldn't dose K if dosing Kno3?

Yes, unless yoyu derived more than say 60% or more of the N from the fish waste.
then you dose K2SO4, or if the NO3 in the tap is high etc.

There are many cases where K2SO4 is useful.
The gH booster is mainlty K2SO4 also BTW, so if that is added along with the KNO3, it's not likely you need to add K2SO4 on top of that.

Regards,
Tom Barr

No, the Lamotte PO4 and NO3 are good!
It's the Fe test method that's poor and it's not the test kit's fault, it's our assumptions about it.

We assume we can relate a residual Fe levels in the water column to plant health.
We cannot.

We can relate a good correct measure of PO4/NO3 to plant health though........

I think we as a hobby do agree, but a little knowledge is a dangerous thing.
The folks that have been at it a long long time tend to see things differently, scientists in the field of aquatic macrophytes are not in any conflict about all this.
Hobbyists? Yea, they are.

You lead them donw the right path, they often do not believe you anyway.
Same with many things.

But that's often how we learn sometimes

The big issue is folks that lack any control over algae, their nutrient levels, use very sad poor test methods, kits etc, lack the eye for good plant growth etc, you want to take their advice?

Now they are trying to help out best they can, but they cannot even help themselves and take their own advice, how can they help you?
Nothing wrong with trying to help, but when you have conflicts about why algae, say BBA, is forming(and they have a problem with it as well) and you tell me it's
PO4 excess, a type of algae I mastered 12 years or so ago......... well........

Algae, plant growth can be complicated, but it does not have to be that way for the "How" part. I know Amano also tries and simplifies things for folks as well.
The "Why" he does not bother with nearly as much. I tend to focus more on that and less on scaping than he does and he runs ADA, that's a lot of work.

I go in depth for many reasons, and many as they learn more can reflect back and look at what I've said they did not understand 2-5 years ago and today it might make a lot of sense.

That's the hope anyway.
I will not understand everything certainly, but I will get things that much more closer and more evolved towards the truth and what is and is not occuring in our planted tanks.

I have resolved the model for why a non CO2 and CO2 enriched tank works well.

That bridges the gap between diverse methodologies.
Substrate vs water column dosing methods, I've also been able to bridge that gap and use the best characters of both to amplify growth.

It took awhile though
About 7-10 years and lot of time and test.


regards,
Tom Barr

Tom,

Thanks for youir comments. I always learn a lot from your posts. Keeping planted tanks can be very frustrating and some of that probably came out in my post. I like the EI method because it does not require the aquarist to constantly test in order to maintain narrow nutritional parameters.

My main reason for using the Lamotte tests is to use them as a learning tool in order to see if I can objectively confirm what I think is going on in my tank. To be honest, I have seen fe deficiency often enough now so that I don't think I need to test. I just don't think I trust my own observations yet after so many past failures.

I have always wondered why planted tanks seem to be so much more popular in Europe than the US. Do Europeans have green thumbs, better information, better products, more patience ?

That said, things really are going pretty well for me. My 30 gallon is about 6 mos old and is now very stable. I've been encouraged enough so that I set up two more tanks. I will post on my progress.


Henry Hatch