Water Column Dosing and Fish

aquabillpers

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Three months ago I set up two identical 10 gallon tanks with an unenriched, inert substrate and soft, acid water. I dosed nitrates, phosphates, and Equilibrium to each to get the water in each up to generally accepted levels, and added Flourish for traces. Lighting was 1.7 WPG. No CO2 was added. No additional nutrients were needed during the course of the study.

Both tanks were planted with E. tenellus and S. sublata as well as other plants.

One tank contained 15 adult female guppies; the other was fishless.

E. tenellus and S. sublata reproduced rapidly in the tank with fish, each increasing from 3 or 4 plants to about 20. Only two runners were produced in the tank without fish. The other plants (hygrophila, bacopa, val) didn't do well in either (probably because of the low light) but they did better in the tank with fish.

Both tanks had some hair algae, with the fishless tank having more.

From this I conclude that the fish added something to the health of the plants, probably ammonia. Someone else suggested that the fish might have added enough CO2 to make a difference in this low CO2 tank.

Has anyone had success with a water column only fertilized tank without fish?

Bill
 

Tom Barr

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Re: Water Column Dosing and Fish

Excellent success without any fish/shrimp or snails.
Better than most tanks with the herbivores.

Regards,
Tom Barr
 

aquabillpers

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Re: Water Column Dosing and Fish

Tom Barr said:
Excellent success without any fish/shrimp or snails.
Better than most tanks with the herbivores.

OK, what did you do differently? More light? Substrate fertilization? Add CO2 in another way?

The idea of a planted tank with only water column fertilization has a lot of charm to me, but before I try it on a larger tank I want to find out what needs improvement in the method that I tried.

Thanks.

And good word wrap technique, too!

Bill
 

Tom Barr

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Re: Water Column Dosing and Fish

I do the basic EI for a high light tank, I packed it with plants from day one.
I can add whatever CO2 I desire also.

If you add lots of weeds from the start, then add the ferts, this works well.
I hardly have any fish/shrimp except in two tanks.

Regards,
Tom Barr
 

aquabillpers

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Re: Water Column Dosing and Fish

Tom Barr said:
I do the basic EI for a high light tank, I packed it with plants from day one. I can add whatever CO2 I desire also.

If you add lots of weeds from the start, then add the ferts, this works well.
I hardly have any fish/shrimp except in two tanks.

OK, but as I said, this was a low light tank with plenty of plants, and you don't suggest EI for tanks like that. The plants just didn't grow in the fishless tank but grew well, at least some of them, in the tank with fish.

Bill
 

Tom Barr

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Re: Water Column Dosing and Fish

With less light, the influence of fish load __is greater__...........
Pretty much as general law.........

But if you maintained the same nutrient totals(eg one from fish load+ nutrient dosing vs just dosing alone), I found the one without plants did better.
But that was higher light also.

Low light would be like a 15 w light on 10 gal etc.
Med, 30w, High 40-60w.


Regards,
Tom Barr