# Do you PMDD?



## MiamiAG (Jan 13, 2004)

OK,

With all the discussion now a days on dosing, please share with us the method you use.


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## panaque (Jan 21, 2004)

I am kind of a low tech guy when it comes to doing things to my tanks. I want the easiest way to reach the end result I want. I use flourish at my weekly water changes every sat. morning. I think a proper substrate is the most beneficial way to give nutrients to plants though. I am going to start using Tropica Master Grow once my flourish runs out. Its the bomb!


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## plantbrain (Jan 23, 2004)

I use a different method on most tanks.
Non CO2 tank 4 gal nano cube open top=> no dosing except for fish food.
Non CO2 tank 4 gal nano cube open top=> as above
No water changes.


20 gal high light/CO2, dosing 3x a week trace, NO3, K, PO4 and fish food
70% weekly water change.
75 gal as above

25 Gal marine tank, Traces, Iodine, Ca, HCO3, KNO3, 3x a week.
60% water change every two weeks.

Test tanks
10 gal 
10 gal 
10 gal 
10 gal

Routine varies.

All tanks have DBS's with organic material in various amounts in the substrate.

Regards, 
Tom Barr


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## MiamiAG (Jan 13, 2004)

Tom,

Interesting but I would agree with a specific routine based on the tank particulars.

What is a DBS? Do you mean DSB (deep sand bed)?

If so, I follow this concept as well. Are you using it for the denitrification benefits as it is used in reef tanks? Or, more for nutrient cycling like I do?

How deep is deep?


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## Phil Edwards (Jan 22, 2004)

I do use PMDD, but not on any type of regular routine anymore. When I did, I followed a regimen which I found to be most useful for a tank, on a tank by tank basis. 

At this point, the only tank I really add stuff to is my discus tank and most of the needed nutrients come from the fish themselves. Since I've got very very soft water I add Turbo Calcium and Flourish Tabs for the swords and the occasional dose of Potassium and Micros if I see things starting to look a little out of sorts.


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## plantbrain (Jan 23, 2004)

DBS- yes sorry, saltwater ac's. Roughly 4 inches average. But the fronts often go to 1-2 inches and the rears go to 5-9 inches depth.

No, no denitrification is really present too much in plant tanks. I measured the NO3 decline over the course of a week ona few plant tanks over the years to this effect. Removing the plants also removes the roots. The roots bring O2 down to the substrate unlike a SW tank, therefore since Denitrifying bacteria like anoxic environemnts to operate efficiently, planted tanks generally are poor places for this to occur significantly. 

But even after removing the roots/plants etc , you still have little delcine in the NO3 levels. I did not leabve the plants out for more than a week so with time, a much larger denitrifying colony may have developed but not much NO3 decline occured in the first week.

I'd say a similar dynamic exist with NH4=> NO2-> NO3 bacteria and plants also.

The plants remove most of NH4 before the bacteria can get it so the bacterial populations are really limited by the plant's usage of the resource.

Therefore you never get large colonies of either bacteria. 
Also, the levels of NO3 are very low compared to many tanks that use denitrifying bacteria.


Regards, 
Tom Barr


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## Rex Grigg (Jan 22, 2004)

I really hate the PMDD idea. It seems that whenever someone new in the hobby "discovers" PMDD they think they have hit the jackpot. I have helped people that also suffer from the Tim Taylor syndrome. If some light is good then more light is better. People running 5+ wpg on a 40 gallon tank. And they think that PMDD is going to help them with their algae problems. Well I guess it would if they dumped a whole bottle into the tank. I'm a big fan of dosing what's needed when needed. The "one Size Fits All" routine is more like a "One Size Fits Some" routine.


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## jerseyjay (Jan 25, 2004)

I follow 10:1:10 (N: P:K) routine. 

All nutrients dosed separately. 

NO3, PO4, TMG+DIY Trace (to save $$$), Flourish Fe, soon wil start dosing CaCO3. 

no K.


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## MiamiAG (Jan 13, 2004)

Rex,

I agree with you on the one size fits all comment. I'll start another thread for that.

Jay,

No K! How are you adding NO3? Are you testing the water to determine what you need? Again, more on my other thread.


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## jerseyjay (Jan 25, 2004)

Art_Giacosa said:


> Jay,
> 
> No K! How are you adding NO3? Are you testing the water to determine what you need? Again, more on my other thread.


I use LaMotte test kit to test NO3. Dosing is done on weekly basis with use of KNO3 and Chucks Calculator. Recently I bought Eheim Liquidoser for convenience.

I won't get into details about NO K or YES K. This was extensively covered in details by few on APD just recently.

Excess or non excess of K is sensitive topic and its another ball game.

General idea.

Research indicates that aquatic plants need a ratio of 10 : 1 : 10 N : P : K

Using KNO3 and KH2PO4 to achive a 10:1:10 ratio..

5 ppm NO3 (1.14 ppm N) : 0.35 PO4 (0.114 ppm P)

If you're using KNO3 as your primary source of N, for 1.14 ppm of N - you're already adding in 3.15 ppm of K.


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## MiamiAG (Jan 13, 2004)

Jay,

We wouldn't want those K good K bad discussions here :wink: . However, I understood from your previous post that you weren't dosing K. In fact, you are KNO3. That's fine. I agree with you on the 10:1:10 formulation.

I maintain my K levels between 10-15 ppm. You won't run into deficiency/toxicity issues at those levels.

Now what would you say is the color of pure water in a white bucket??? :lol: Just kidding...


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## Rex Grigg (Jan 22, 2004)

I'm with Jay here. I add no K beyond what is supplied by the KNO3.


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