Set up a "odds and ends" 20 long. Got peat and mulm in the bottom. Topped with 3" profile, onyx and flourite (onyx from another tank and flourite from a tear down) Had a single 24" tube VHO set up with an aquasun bulb from the tear down as well. Retro fit it into the full hood and there ya go! This is gonna be fun! I am gonna use just a power head to move the water and havent decided on a heater or not. I figure the "75 watt" VHO wont be too much since it is a) in a full hood and b) not using a decent reflector at all. A lot of wasted light but its what was on hand + I really like the color of the aquasun bulbs. Makes the fish and plants look great

75w on a 20g is 3.75wpg. Even without a good reflector isn't this way too much for a non-CO2 tank?

I currently have 2 20 gallon tanks set up with 125 Watts of light on each.

I put the same types of plants in each.

One tank is CO2 dosed in large quantities.
Also dosed are Seachem Flourish
Potassium Sulphate once a week with water change
KN03 and KH2PO4 every second day
Seachem Flourish every second day.


One tank is a "Diana Walstad" tank.
About once a week I dose the same things I'm dosing in the CO2 tank.

After 3 months of observaions I have noticed:
Water in the CO2 tank is crystal clear, while the "Diana" tank is slightly darker.
After a few days water was green in the Diana tank, but cleared up after a coule days. This didn't happen in the CO2 tank.

Plant growth has been close to progressing at the same speed.
Algae growth in both tanks has been minimal, but there is a development of a type of branchy algae growing on the slower growing plants in the Diana tank.

From experience, I know that the "Diana" tank will not hold in for the long term. I expect it to start slowing down in the next 3 months.


Cost of the Dianna Walstead tank. $125.00 including the lighting.
Cost of the CO2 tank (complete with pH controller) $1200.00.

They(non CO2) start well out of the gate, you can add nutrients to keep them going though, start dosing SeaChem Eq, KNO3, KH2PO4 etc.

It's amazing they do grow as fast as they do when you add the right nutrients once they begin to hit the lull.

The same thing use to ocurr with CO2 methods till folks started adding PO4...

Regards,
Tom Barr

In the Walstad approach, the eventual depletion of the soil nutrients is offset by the fertilizer that well-fed fish produce.

I have one soil-based tank that has been set up for eight months and needs no dosing, and another 10 month old tank that has required dosing from the third month, although the amount needed is decreasing as the fish population grows and the plant growth slows down.

All natural aquarium environments are different and perhaps more interesting than those with more controlled environments. Or perhaps not, depending on one's objectives.

Bill

The fish waste alone is not a balanced source of plant nutrients.
Some plants will grow, but many will not.
The question I asked some years ago was why.

The plants will do better if you add just a small amount once a week(this is not outting you or anyone out too much?) of SeaChem Eq and KNO3/KH2PO4.

Nothing complex, nothing high tech, add 3 things once a week.
This allows you to grow most any plant.

It also removes the need and mess for soil should you go that route.

Regards,
Tom Barr

Ms. Walstad and her followers claim that they grow aquatic gardens in soil tanks with only fish food for nutrients. As I said, I have one tank that has worked well for 8 months without dosing, and another that needs dosing. In the former, NO3 and PO4 levels have been constant for about 5 months. I think that might have more to do with the high fish population than with the soil in the substrate.

I have another tank that was set up as a fry tank, with an inert gravel substrate and a few plants. It had bad BGA and other algae problems, I'm sure because of poor nutrient levels. After a few months I got sick of looking at it as it was. I treated the algae problems and dosed it to bring the NO3 and PO4 levels up to a reasonable level. Since then the 30 well-fed, adult guppies in that 10 gallon tank (I know, too many) seem to be producing what the plants need, because they are growing well without any additional dosing, and there is no algae problem.

I intend to set up a tank using the method that Tom outlined, as soon as I can find a local source that sells Equilibrium in less than 5 year quantities.
In fact, maybe two tanks: one with fish and one without.

All natural tanks are different.

Bill

So you can have Gloss, A reineckii or hairgrass growing in there?
\Lwet me see a nice field of that, then we can talk which method is able to supply the nutrients for all, not just some plants.

I agree fish waste alone can supply some plants well.
She and others concede that some plants wane for unknown reasons, I know the reasons..............
She speculates, incorrectly, that allelopathy is a possible cause for this.
If allelopathy is the cause, why don't I have trouble?

Like PO4 excess = algae, if I aded PO4 I should see algae, but I don't.
If I try and grow these same plants that do poorly in non CO2 tanks, why am I not having trouble?

Thus it cannot be allelopathy if that is what is preventing the plant from growing in my tanks...


Yep, I'd expect this.


Ahhh, now you are thinking!
This will greatly help you see the difference between what the fish loading will add vs the inorganic nutrients.

I have done this for a few years now.
That's how come I know what needs to be added.

You can order EQ from most mail order places, 500grams runs 5-8$.


Yes, so removing the main input variable, the fish load/food/waste, takes care of that.

This gives you more control of the inuts and outputs.
The water chanegs are still not done, weekly dosing is adequate also(not too hard of a routine!)

Diana has done a fair amount of work and research, but without testing a control with out the fish etc, knowing what plants need at higher CO2/light values, you really are guessing.

That's fine when the growth rate is slowed down, but the main factor in the success is the lack of water changes.

That slows down the uptake rates so that if something does not make it, it will take a long time, liklewise any nutrient deficency takes a long time to appear and it can be remedied by adding more fish/fish food etc in general, or you can add SeaChem EQ and a little KNO3/trace/KH2PO4 etc as well.

Fish food alone is very easy and what many seem to desire to achieve the balance, but a better balance can be achieved without that fish centric attitude and philosophy.

Balance the needs of the plants first(plantcentric thinking), then feed the fish whatever.

The fish waste is secondary, icing on the cake and when you dose once a week at small amounts of inorganic ferts, this uoptake of fishj waste is further maximized and the tank does better and grows better.

This allows you to keep a non CO2 planted tank with more plant species in better health, higher growth rates(but not insanely fast!), better aquascaping designs and layouts, with only a small dosing weekly routine and less variation in the soil type since I suggest using Onyx sand/leonardite/mulm/peat.

Less mess, easier to move plants around, more plant species etc, these are not small gains...............

That's worth a lot for only a few simple modifications.

Similarly, I did the same thing to Paul and Kevin's PMDD's theory.Overall, the idea was great, just needed a few small changes and some clarity abiout why things were occuring.

Both the PMDD and the Non CO2 method's reason's as to why algae grow and what plants need etc are incorrect.

The same will occur with non CO2 methods as it did in CO2 enriched systems and is happening in Marine planted tanks also.

Which is cool, since now we can grow at many different rates, have far more control over what we can keep, different routines to suit lazy and more amibitious folks.

Ultimately this means more success with planted tanks.
I will say Paul and Diana did extremely well, I'm just tweaking things to make them consistent and stable and going back and testing the notions as to why.

From that, I know what are the main players in the system/method and then know how to go about tweaking it.

Regards,
Tom Barr

What about nightly buildup of CO2? In the morning the CO2-level could potentially be substantial with very low surface agitation, and if that is so it would be good with above normal circulation-levels in low-techs?

But low tech = no CO2...................so it shouldn't be an issue surely.

Ian