Hi Tom,
welcome to AF and thank you for accepting my invitation.
To clarify what is happening to other users I can tell you that in the last weeks I contacted Tom and asked him to give as an interview:
1° Question

Who is Tom Barr
I read on the web that you studied Biology. How did your studies helped you to become one of the most famous aquascaper in the world?

Hellow everyone. I studied Biology all my life. My dad was a Cave Biolgist, studied beetles and taught at the university at Kentucky. His friend and next lab over was a fish Biologist, studied Darters. I selpt a lot in Biology classes until the upper division classes and Graduate school. That's where the suffering begins, haha. I went back to college after dropping out 4 X. I was about 30 years old when I decided to get serious and finish. I'd already had a strong interest and impact on the planted tank community by then. So plant biology was very applied for myself. I also did ample graduate work on algae and bacteria. The plant biology is fairly well understood, however hobbyists do not want to hear that. Logic is often not accepted by the public.

Question 2
Probably these are the most obvious questions:
What is the Estimative Index? Can you explain µS/cm why you started studying tanks fertilization, and how did you ended up with the EI method? Which fertilizers do you use?
Question 3
But you are famous for more than this: first of all, you have been the first one to tell the world that plants grow better with PO₄^3-! But I never read in your papers about NO₃^-. Why?
Question 4
Moreover you don't dislike Walstad techniques. You claim that good fertilization on water column can replace ground fertilization, and that it is even possible maintaining a tank without water changes. This is more or less our approach: we try to understand plant needs, avoiding to use fertilizers when unnecessary.
Can you explain µS/cm your point? Question 5
Aquaria are a bit like children: one cannot say which is the favourite... But let me ask the question: do you have an aquarium which you love above the others? How old is it, and how much time do you dedicate to it?
Can you put a pics of it and of some others your acquaria? Question 6
You claim that DiY is not for all, why? Is it because not everyone can do by himself? Or do you think that commercial products are better? Question 7
How do you see the impact of the internet on the aquariophily? Every information is now promptly accessible: just Google it! But it is becoming increasingly hard to get the correct information, without being swamped by inaccurate advices. Question 8
We constantly see new products proposed for our hobby: new LED lights, CO₂ systems, heaters, refrigerators... But also new tests, and chemicals to treat waters. Is all this new technology making aquarium keeping easier, or it is just a way to avoid to understand how an aquarium works? Question 9
Now a personal question: is this aquarium passion/hobby also an income source, or do you have another job? Question 10
A last one:
What would you suggest to someone that aims to become “the new Tom Barr”?

Question 2
Probably these are the most obvious questions:
What is the Estimative Index? Can you explain µS/cm why you started studying tanks fertilization, and how did you ended up with the EI method? Which fertilizers do you use?

It's just a common sense thing many aquarist were already doing. Large, frequent water changes and then dosing right afterwards. Weekly did not do as well as 2-3x a week, so by simply reducing the water changes to once a week and dosing 2-3x and guessing what the maximum uptake might be, you can reset once a week instead and dose 2-3x a week. Easy. The good part about this is that you no longer need to dose or worry much about having enough fertilizers. Thus you do not need to test or worry about ppm's. Most are familiar with teaspoons for baking and cooking. So it's simply adding non limiting ferts (but you can run it lean if you wish also) and doing a weekly water to prevent any build up of fertilizers. Some folks use a TDS meter and when it gets about 300-400 µS/cm above the tap water or make up water used, they change the water. There are a few ways to do this to get away from testing much, if at all. TDS meters are quick but they do not tell which ions are bulding up.

EI is simply 90% of PMDD from th Krib but I tossed in the PO₄^3- dosing and got rid of the testing and upped the % water changes to 50% weekly to make the math easier. We did not have dosing calculators on line back then. So none of this is really "my idea" per se. I just argued and found this mix worked well.

PMDD worked well for many, but many still had issues, whereas I did not. My tap water had about 1 ppm PO₄^3- and doign large frequent water changes helped, a lot. So the other plant hobbyist came to my home and noted the radical differences and called my tap water magic. Eventually they came back and tested it for PO₄^3-. Then my tank. Tank was 0 to 0.2ppm, tap water was about 1.1 ppm. Clearly the PO₄^3- was goign somewhere and high PO₄^3-(over 0.2ppm) =algae was false.

I use basic ferts:

KNO3
KH2PO4
GH booster a 3:1 mix of CaSO4 and MgSO4
Trace mix(3:1:1), CMS+B:DTPA Fe: Gluconate Fe

I dose 2-3x a week
CO₂ is rich if I use the gas.
I do not use glutaraldehyde.
Added in 6 minutes 59 seconds:

But you are famous for more than this: first of all, you have been the first one to tell the world that plants grow better with PO₄^3-! But I never read in your papers about NO₃^-. Why?

I am not famous beyond a small group of planted aquarist.
I did not discover PO₄^3- and growth in aquariums, but I provided the control for the test that showed it was not the cause of algae.
Steve Dixon actually proposed thr hypothesis there. I provided the aquarium and example.

Later, he went back and dosed KH2PO4 and his tank responded like mine.
At that point we all agreed that the hypothesis was incorrect that suggested PO₄^3- above 0.2 ppm causes algae issues in planted tanks. Algae must be caused by other factors.

Steve's tap water had no PO₄^3- to speak of in it, mine was rich. So we got lucky.

NO₃^- was more about fish health as far as hobbyists claiming the need to have it so low, 5ppm etc.
But many over dosed and noted some plant species did better at 10-20ppm.
Some claimed some species stunted at higher levels.
But Liebig's law applies.

If you limit one thing, it'll reduce say CO₂ demand. When you remove that limitation, then CO₂ becomes limiting and you see stunted tips.
Same for K+ at higher levels and other fertilizers.

I suppose the PO₄^3- was a larger myth and was central to many aquarist hypothesis about algae blooms. Most of the older research suggested it.
But new research suggest there is no relationship in natural lakes and ponds where plants are present and the lakes do not freeze over.

Moreover you don't dislike Walstad techniques. You claim that good fertilization on water column can replace ground fertilization, and that it is even possible maintaining a tank without water changes. This is more or less our approach: we try to understand plant needs, avoiding to use fertilizers when unnecessary.
Can you explain µS/cm your point?

I know her personally and Dorothy Reimer as well. The latter perhaps is somewhat a mentor to her as well as many in the Aquatic Gardener's Association and the Aquatic plants mailing digest(APD). You'd have to ask her directly. We had a good trip together at a speaking event in Australia together. My view has always been observational. If someone can and has done something a certain way, then the method is clearly valid. She showed that. Supported it, got many things correct, a few things incorrect, but unlike myself who did not write a book back in 1998, I also had a few things wrong myself, but no book for people to point what those things were.

Soil works very well and is easy for most people. It provides a back up. It can be inconsistent for new hobbyist however. They can make a mess. They can not follow the advice and take short cuts. Then such methods get a bad name. Then people say/claim it does not work. The largest factor I think preventing more hobbyist from not adpoting the method for at least 1 or more of their tanks boils down to one basic issue: a lack of nice aquascapes usign the method. That's changing and many higher levels aquascapers are starting to try the method and have stunning results and so much easier care and routines.

A pretty scape(or an ugly one) does not define a method. A nice aquascape can be forced with any method. It might be a lot more labor and work than a different method. But it can be done if the hobbyist is skilled.

I wanted to take a different approach back in the early 2000's than her approach just to see about algae and the water column.
So I estimated non CO₂ plant growth rates based on CO₂ gas amplified growth rates, which were about 10-20X faster with the addition of CO₂ gas enrichment. So I ltook EI and cut that into 1/20th dosing. I dosed once a week, fairly easy routine. Long intervals between water changes. Much less trimming.

This is what many planted hobbyists say is their goal.
Even the ones who use the CO₂ gas.

But to be clear, the hobby would not be anywhere near what it is with out the CO₂ gas. That makes intensive gardening possible. But that's also a lot of labor and work to keep a well trimmed and groomed plantd tank. But I like to keep several tanks, so more are going to be non CO₂. Shrimp breed better and many fish are happier in non CO₂ tanks, they just have far fewer issues than CO₂ tanks, less algae, more stable etc.

As far as water column versus the sediment: both locations for nutrients is the best management. But either can work well isolated also, many do not have access or the $ for a commerical sediment like ADA aqua soil, many will just use sand. This gives them a good option. But overall, this applies to CO₂ gas enriched aquariums also: both locations works best for management for fertilizers. You have a back up for each method basically. One runs out, the other serves as a redundant source for fertilizers.

Algae is very minimal in the non CO₂ methods: sediment rich, water column rich or both rich. Black brush algae(BBA) is almost non existent. Even if any algae does occur, often it's easy to remove manually.

Some caveats: I do water changes, 2-3x a week for the 1st 1 month, then once a week for another month. After that, not much, if at all.
You can use the TDS meters to decide when to do a water change. If after a water change you are at say 200 µS/cm, and it creeps up to 350-400uS after 2-4 weeks, you likely need to dose less or see if that level goes down before dosing again. I tend to just do a water change and not dose as much for the next 2-4 weeks and see. It's not hard and resets things. I try and choose plants that are get along well together as far as growth rates. Some emergent plants are always a good idea for the 1st few months anyway. Most of the hard plants will grow, iwagumi style layouts are possible with some species etc, but the growth rates are slower. Leaf sizes are smaller and colors often not as bright. Some species hold the color, e.g. Alternathera reineckii does well for me when I grew it.
Added in 12 minutes 13 seconds:

Aquaria are a bit like children: one cannot say which is the favourite... But let me ask the question: do you have an aquarium which you love above the others? How old is it, and how much time do you dedicate to it?
Can you put a pics of it and of some others your acquaria?

No not really. Some I like since they are operatign at a much slower but just as interesting rate, others grow fast, but require more labor.
CO₂ or no CO₂, lower light or high light, no water changes vs lots of water changes etc.

I suppose I hold no bias towards any methods, mostly because I have mastered all the various methods to a high level: e.g., I can aquascape with any of them well. When you get to this point, then none of the ego driven banter on forums bothers you and you can rip into those who claim their one method is best for everyone. Ego is the anesthesia that dulls the pain of ignorance.

As we all have different goals, no single method will ever be all things to all hobbyits goal's. So in order to help more people and to not be stuck in a singular method, it is wiser to learn how to use each method well. Just because you might have trouble with a method, does not imply others will. Some methods such as the older PMDD had a limiting factor as part of the method, those are not that great for that reason........but they still work, they are just rarely the best management for most people's goals. As such, not many use them today.

Sediment + water colum dosing methods work well for most people's goals.
CO₂ is the hardest thing for most people, particularly in the USA as they seem to think more and more high powered light is best.
Europe and Asia have less issues with this however.

I keep aquascapes I like for perhaps 5-8 years at most before redoing the design. They tend to be pretty easy to care for based more on plant choices.
Here's a video: I spent maybe 1 hour a week on it.

You claim that DiY is not for all, why? Is it because not everyone can do by himself? Or do you think that commercial products are better?

I strongly prefer DIY, but some things are better left to professionals, nice clean rimless tanks I can and have made myself, but I prefer to hire someone else to do that. They are not cheap, so if you have limited $$$, and the time to do it..............then sure. For soils, ADA aqua soil seems the best and it's easier than DIY soil mixes. Fertilizers: emntirely DIY. But some all in one fertilizers are easier until the newer hobbyists get more experienced. Or if they only have one smaller aquarium, then the cost factors are smaller.

In many cases, it can be hard for many to get some DIY fertilizers, but most sell in the countries that the hobbyists live in these days, not back in 1990's.
I might have to drill a glass tank for a client. So there are some things I have to do myself and cannot hire out or buy commercially beause, well, I am the contractor.

Commericla products allow new folks access without listenign to 101 chefs on a forum jocking to tell them what to do and often get inimidated. whereas a local aquarium shop they can talk to and see the results in person. Yes, they pay for it.............but thr shop has a right to make a profit and it's not an easy business to make much money at. Most shop owners are in business because they love it, not to make a lot of $. PO₄^3- = algae myths have been reduced as many products now have PO₄^3- in them for plant fertilizers. SeaCjhema nd Tropica's products come as a direct conversation with me back in the 1990's. Many soon followed thereafter.

So like sediment vs the water column for dosing, having DIY and commerical products tends to be best for the hobby.
I can work with a store owner and their product line or help them develop one....or I can work with DIY hobbyists.
As with methods and aquascape designs, no one method or design will meet all goals, the same is true here as well.

Added in 4 minutes 56 seconds:

How do you see the impact of the internet on the aquariophily? Every information is now promptly accessible: just Google it! But it is becoming increasingly hard to get the correct information, without being swamped by inaccurate advices.

It's mixed. Good information gets spread. So does misinformation and just plain bad information.
Generally this is even more true for Bonsai than aquatic plants.

I suggest finding a local club, learn for the locals till you are better than they are:-)
NBAT groups in the Netherlands are very good for this reason, but membership is slowly falling.
The old men and women showing the new people in person how to improve.

This is what the hobby is about and how it gets better, the new generation must become involved and help the next generation.
Amano saw this clearly, many of the newer people Such as Oliver Knott, George Farmer and many others are in these groups.
I saw a 10 year old girl here in the USA do a better aquascape than most any adult in a meeting. She will be really good and is already.

Added in 4 minutes 55 seconds:
There are many issues with some of the plants in this video, but gives you an idea of where I was going, Erio type 3 is poor lookign here, I've done much better with these species the last few years and tried to get things into tip top shape.



Added in 4 minutes 15 seconds:

We constantly see new products proposed for our hobby: new LED lights, CO₂ systems, heaters, refrigerators... But also new tests, and chemicals to treat waters. Is all this new technology making aquarium keeping easier, or it is just a way to avoid to understand how an aquarium works?

New lighting is often interesting, LED's cause a lot of confusion however. They could be much better I think.
But there's not a huge market for the light makers for the planted market.
Even ADA takes a long time to get things and new tech to the market.

Test and chemicals are not that useful in my experiences.
Water change tends to fix those much quicker.

I am for technology, but only if it simplifies.
I do automated water changes for clients and control monitors. So I can check remotely if things are going well.

Like any information: more is not always better.
Added in 6 minutes 10 seconds:

Now a personal question: is this aquarium passion/hobby also an income source, or do you have another job?

I went to college and got my PhD in plant biology. But I spend less time doing my business than if I took a research career 40 hours a week for the state. I got that job and quit when they would not allow me one day off a week to do the business. I worked and went to college for about 10 years and did the business as well. So I have had a job, a business and full time student life. Now I just have a business for 2-3 days a week, I like the free time!

I taught college biology for awhile in the past and will try hard to do that as a part or semi full time career here this coming year. Those are not easy jobs to get.

So yes, the hobby is my source of income and I do pretty well. But I year for some more intellectual one on one type of work, research and teaching.
Just not 40 hours a week, teaching has summers off and is good for kid's schedules if you have children. My wife works the same position I once had, so it's good one of µS/cm has a flexible schedule.
Added in 6 minutes 21 seconds:

A last one:
What would you suggest to someone that aims to become “the new Tom Barr”?

Learn each method well. Learn to really focus on aquascaping and the art aspects.
You learn by doing, so do many aquariums as you can possibly can.
Same is true with Bonsai and most types of farming and horticulture.

George Farmer, Juri J. and Oliver Knott have done well, there are many in the EU you can speak with how they made the jump.

I have a few mainteance clients that are well off. I sell a lot of driftwood wholesale that I collect. I am also a freight broker so I can find thr cheapest friehgt rates for driftwood in the USA and Canada. Overseas is far harder and generally the buyer needs to get a container load's worth(about 20 pallet's worth), I am not interested in that level. But 2-8 pallets a month is good.

Academically: do what you love. Seek out those doing what you like and ask them directly about your research interest and questions.

You are a realy big person

we wait Paky for a correct translation
Thank you very much Mr Barr ^:)^ ^:)^ ^:)^

Is possible to talk about some points???

cicerchia80 ha scritto: ↑ Is possible to talk about some points???

Certainly

Tom

Aggiunte tutte le traduzioni sotto spoiler
Infinite grazie a @nicolatc che me le ha fatte ^:)^

PMDD worked well for many, but many still had issues, whereas I did not. My tap water had about 1 ppm PO₄^3- and doign large frequent water changes helped, a lot. So the other plant hobbyist came to my home and noted the radical differences and called my tap water magic. Eventually they came back and tested it for PO₄^3-. Then my tank. Tank was 0 to 0.2ppm, tap water was about 1.1 ppm. Clearly the PO₄^3- was goign somewhere and high PO₄^3-(over 0.2ppm) =algae was false.

Nonetheless, I think I read on a forum that you normally keep PO₄^3- at 4 ppm or higher, right?

I use basic ferts:

KNO3
KH2PO4
GH booster a 3:1 mix of CaSO4 and MgSO4
Trace mix(3:1:1), CMS+B:DTPA Fe: Gluconate Fe

Which is your opinion on plain NO₃^- fertilizers? Do they work better than mixed nitrogen ones (ie with nitrate nitrogen, ammoniacal nitrogen and urea nitrogen) in heavy planted tank?

CO₂ is rich if I use the gas.

CO₂ estimation in CO₂ enriched tanks is a bit tricky under certain circumstances, for example tables don't work well if you use peat moss, hardwood leaves, drift wood, etc.
Which method do you use, and which one work best in most cases in your opinion?
And finally, which is the typical CO₂ range in non CO₂ tanks, if you have ever measured it?

NO₃^- was more about fish health as far as hobbyists claiming the need to have it so low, 5ppm etc.
But many over dosed and noted some plant species did better at 10-20ppm.

Do you think 10-20 ppm is an optimal level? In other words, can we say that this level is even a limiting factor for some species like Egeria?
Conversely, which plants, in your opinion, do better with low nitrates?
Someones claim that some plants cannot turn red if NO₃^- are higher than 10 ppm. I’ve personally observed this on a simple Phyllanthus, but perhaps it was just a coincidence.

I suppose the PO₄^3- was a larger myth and was central to many aquarist hypothesis about algae blooms. Most of the older research suggested it.
But new research suggest there is no relationship in natural lakes and ponds where plants are present and the lakes do not freeze over.

Well, in a forum some guys showed you a scientific research stating the opposite and your straight answer was: Aquarium is not a lake. I agree with you. Indeed, which lake has 30 ppm CO₂, or balanced fertilizers? So, the comparison is useless.

But I like to keep several tanks, so more are going to be non CO₂. Shrimp breed better and many fish are happier in non CO₂ tanks, they just have far fewer issues than CO₂ tanks, less algae, more stable etc.

As far as water column versus the sediment: both locations for nutrients is the best management. But either can work well isolated also, many do not have access or the $ for a commerical sediment like ADA aqua soil, many will just use sand. This gives them a good option. But overall, this applies to CO₂ gas enriched aquariums also: both locations works best for management for fertilizers. You have a back up for each method basically. One runs out, the other serves as a redundant source for fertilizers.

Algae is very minimal in the non CO₂ methods: sediment rich, water column rich or both rich. Black brush algae(BBA) is almost non existent. Even if any algae does occur, often it's easy to remove manually.
:-\

Could you, please, elaborate on this? Do you find that tanks work better with no CO₂ enrichment? I find them even more difficult to care instead.
Which is the specific relationship between CO₂ and algae?

New lighting is often interesting, LED's cause a lot of confusion however. They could be much better I think.

But which one do you prefer, LED or T5? Specifically built for aquaria, or general use?
Which lighting would you suggest for heavily planted tanks?
Regarding the T5 from hardware stores, what power and color temperature?

1. I keep about 3-5 ppm PO₄^3- 2. I use mostly KNO3, I've not found adding NH4 helps and can lead to more issues for many aquarist. NH4 works well in thr soil as it binds to clays, but not so well in the water column. 3. You can do large water changes if you have tannins, peat etc. Then take the reading. Set the CO₂, then ingore the pH etc once the peat or tannins are added back to the water. As long as the flow of CO₂ is stable, the ppm's should be also, regardless of pH or KH.

You can use the relative CO₂ pH method also. 1 pH unit drop = about 30 ppm, 1.2 pH drop = 45 ppm and so on.
Or do large water changes with RO/DI and add baking soda to give say a 1 KH.

There are also other methods.

Non CO₂ tanks vary widely and depending on time of day, can go from 8-10 ppm to zero. 4. Not sure, some plants seem better with low nutrients in the water but rich sediments, but only a very few(20-30 species), the rest do not care.
But 10 ppm or over is good. I have very red plants at higher NO₃^-. There are many other factors to good growth that enhance red color that have nothing to do with NO₃^- ppm. 5. Research can show the opposite, but the research may have poor assumptions. You need to carefully look at the research before assuming it applies and it suppoorts what you say. The University of Florida does the most research on aquatic plants due to weed control and the 4700 lakes that have over 4 hectares. Subtropical and does not freeze over, like our own aquariums.

CO₂ can vary from 5 ppm to 30-40 ppm. Depends, springs are richer, but larger lakes can have a lot of CO₂ relative to the plant biomass. Ferts can be in the water or the sediment. 6. Non CO₂ tanks are easier, but hard for many newbies because they do not listen to all the advice, they just hear "no CO₂" and like that part.
Many add too much light also, but that's true for CO₂ enriched tanks also. 7. T5 lighting, a few companies have made or make good LED, but they cost a lot for good ones I like.
Most any color you like works for plants, so you should likely try out various types and see what suits you for T5.