# PMDD & MKP Dosing - I think I am overdoing it...



## tennis4you (30 Nov 2008)

I have been using PMDD and MKP for a few months now ever since I set up a pressurized CO2 tank.  I went off of a rough stab from someone on how much to dose, but that was when my plants were very small.  Since I started the CO2 and the ferts the plants have exploded in size.  I have a lot of swords mainly due to the fact I have large fish (due to my prior planting days) and I know swords will stay rooted well with the big fish banging around in the tank.

I was reading about dosing at the following link:  http://www.thekrib.com/Plants/Fertilizer/pmdd-tim.html  and it made think I may be dosing too much, but I am at a loss.

One main reason I am starting to doubt myself is the BBA that is now being treated for the 3rd time since I have gone with the ferts.  I do not want to keep treating BBA, I want it out of my life for good.  I believe my CO2 is constant, but I do not know the ppm for the tank since I do not have the water people order to do the proper testing in the drop checker.

Here is a picture of the tank so you can see how "heavily" or "non-heavily" the tank is planted:





The plants have all grown pretty fast.  I do see a handful of yellow tips on the swords, I am sure that means something...

Below are some answer to questions people might ask...

Right now I am currently dosing 25mL of PMDD and 4 mL of MKP. 

PMDD is mixed 1/4 cup of mix w/ 500mL of water.
MKP is mixed with 3/4 tsp of MKP w/ 1 liter distilled water

I am running 2 Eheim 2217 Canister Filters, 1 on each side of the tank.
I have 2 power heads running.  PH and Filters = 10x turn over per hour

I have 145 watts of light, T5 - Nova Extreme.
Lights are on 8 hours per day on a timer.

CO2 is about 3dps, I raised it to about 5dps since the BBA came back.

Ammonia = 0
FE = 0 (It always reads zero, I am starting to wonder about my test kit)
Nitrates = 40 - And I just did a mega water change 3 days ago and it just now read 40!!!

I do about a 30% water change every other week.  I am starting to think I need to make that weekly.

I have tried looking up the dosing calculator, but I just do not know how to use it for PMDD and MKP.  I am just at a loss and I want to make sure I am doing this right.

I apologize if this is starting to look like a duplicate thread from the BBA thread I started in the algae thread.  I thought I should start one solely for dosing as I am starting to doubt my methods.

Thanks for all your help, you guys are always awesome!!!


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## Ed Seeley (30 Nov 2008)

BBA is often linked to low or erratic CO2.  You need to find out the ppm of your CO2 in your tank!  If you can't buy 4dKH water then you need to make some.  I used RO water and a KH test kit to make mine.  It may not be as accurate as the bought stuff, but it's more than good enough for our needs.  What you need to do is start with 0dKH RO water and add Sodium Bicarbonate to get to 4dKH.  Most KH test kits measure 5ml of water and give you a results to the nearest dKH.  If you use 10ml it's accurate to 0.5dKH.  Therefore 20ml = 0.25dKH, 25ml = 0.2dKH and 50ml = 0.1dKH.  The only problem with the larger volumes is that you could use a whole test kit doing one sample!!!!  Personally I measured mine using 20ml of solution so I was accurate to the nearest 1/4dKH and it has worked fine for me.  I also found roughly how much Sodium bicarb to use on the internet first to help.  Then it's just a case of trial and error, adding some bicarb, adding some RO until you get an accurate reading.   It didn't take me long.

Also, in a big tank, you may need two (or even more) drop checkers so you can put them at each end of the tank to check how the CO2 is distributed.

Bear in mind that your CO2 distribution is linked to the biomass of your plants (more plants use more CO2) and your flow (filters slow between cleanings and the increased plant mass blocks the flow more) which means CO2 isn't distributed as evenly.  This is one reason why lots of us use tons of flow in our tanks.  I have a Hydor Koralia (1,800lph) and the internal Juwel filter (600lph) in my 180l tank (rated flow is 13.3 times the volume!).


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## GreenNeedle (30 Nov 2008)

To make a 'roughly' 4dKH solution you need the following:

5Ltrs DI water
1 Ltr DI water
6g Bicarb

First add the 6g Bicarb to the 5Ltr of DI which should give you in the region of 40dKH water.  Shake it well and then using a syringe take 10ml of this solution and put it in a clean, dry, sterilised container (to make sure the container has no contaminants in it)

Add 90ml of the unused DI water (the stuff without bicarb in it) and then add it to the 10ml of 40dKH solution and you now have 100ml of approx 4dKH water.

The solution won't be exactly 4dKH and there never was agreement on the actual amount of bicarb in the mix due to moisture contained in the bicarb etc but will give you a 'close' version.

Then buy 2-3 drop checkers and spread them through your tank.

AC


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## Nick16 (30 Nov 2008)

can i ask what is PMDD and MKP? im new to all the terminology and would like some help. i guess it ferts but thats about it!!!


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## tennis4you (30 Nov 2008)

Nick16 said:
			
		

> can i ask what is PMDD and MKP? im new to all the terminology and would like some help. i guess it ferts but thats about it!!!



MKP is Mono Potassium Phosphates
PMDD is Poor Man's Dosing Drops which is a mix of just about everything but phosphates.

Thanks for the help with the 4dkH water, I will check it out.

Any thoughts on the dosing amounts I am using (or should be using) though?


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## Nick16 (30 Nov 2008)

where can you get the stuff to mix up this? is it cheaper than buying tpn+? what advantages does it bring?


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## tennis4you (30 Nov 2008)

I have found it to be much cheaper than buying Flourish and other ferts already mixed in a bottle.  This is also more comprehensive than what I was using and paying a ton for!

I think I have spent $24.00 of ferts and it looks like it will last me a year.

Here is where I got it all.  Shipping costs $6.00 from what I can tell so far:

http://www.aquariumfertilizer.com/Store.php

I was intimidated by dry ferts at first, but it tells you how much water to mix in right on the package so you can mix your own ferts easily enough.  The only thing after that is figuring out how much to dose.  That of course is my question right now that I am seeking answers for.

Hope that helps!


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## Nick16 (30 Nov 2008)

is there anywhere i england that sells that stuff? i really need a trace elements mix, but i dont know what goes into it, otherwise is TPN+ for me!!


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## tennis4you (30 Nov 2008)

Nick16 said:
			
		

> is there anywhere i england that sells that stuff? i really need a trace elements mix, but i dont know what goes into it, otherwise is TPN+ for me!!



The other should be able to answer that one better for you.


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## tennis4you (30 Nov 2008)

I do have yellow tips on the plants.  Should I up the dosage of PMDD or MKP?


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## milla (30 Nov 2008)

Nick16 said:
			
		

> is there anywhere i england that sells that stuff? i really need a trace elements mix, but i dont know what goes into it, otherwise is TPN+ for me!!




Here you go  

http://www.aquaessentials.co.uk/index.p ... cts_id=545


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## Ed Seeley (30 Nov 2008)

tennis4you said:
			
		

> I do have yellow tips on the plants.  Should I up the dosage of PMDD or MKP?



I'd sort the CO2 out first and then see how things are with the plants.  If you still have yellowish tips on the plants then you can try upping the ferts.  It won't cause any harm if you do.


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## tennis4you (30 Nov 2008)

Ed Seeley said:
			
		

> BBA is often linked to low or erratic CO2.  You need to find out the ppm of your CO2 in your tank!  If you can't buy 4dKH water then you need to make some.  I used RO water and a KH test kit to make mine.  It may not be as accurate as the bought stuff, but it's more than good enough for our needs.  What you need to do is start with 0dKH RO water and add Sodium Bicarbonate to get to 4dKH.  Most KH test kits measure 5ml of water and give you a results to the nearest dKH.  If you use 10ml it's accurate to 0.5dKH.  Therefore 20ml = 0.25dKH, 25ml = 0.2dKH and 50ml = 0.1dKH.  The only problem with the larger volumes is that you could use a whole test kit doing one sample!!!!  Personally I measured mine using 20ml of solution so I was accurate to the nearest 1/4dKH and it has worked fine for me.  I also found roughly how much Sodium bicarb to use on the internet first to help.  Then it's just a case of trial and error, adding some bicarb, adding some RO until you get an accurate reading.   It didn't take me long.
> 
> Also, in a big tank, you may need two (or even more) drop checkers so you can put them at each end of the tank to check how the CO2 is distributed.
> 
> Bear in mind that your CO2 distribution is linked to the biomass of your plants (more plants use more CO2) and your flow (filters slow between cleanings and the increased plant mass blocks the flow more) which means CO2 isn't distributed as evenly.  This is one reason why lots of us use tons of flow in our tanks.  I have a Hydor Koralia (1,800lph) and the internal Juwel filter (600lph) in my 180l tank (rated flow is 13.3 times the volume!).



What is RO water?  If I filter the water coming out of the tap will that do the trick?


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## tennis4you (1 Dec 2008)

OK, I just used filtered tap water and made the 4dkH water.  I put the drop checker in about 4 hours ago.  The water is a very nice green.

However, this is after I raised the CO2 4 days ago or so from about 3 dps to 5dps so I have really raised it a lot compared to what is was.  I wonder if that was part of the problem.

I put the drop checker in the middle of the tank where most of the bba is.  I will try moving it around now and see if I can find any dead spots.


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## ceg4048 (1 Dec 2008)

tennis,
          RO water refers to water processed through a Reverse Osmosis filter. The filter is a neoprene material and can be thought of as a mesh with pores so small that only particles the size a water molecule or smaller can penetrate. The result is that the dissolved salts which are responsible for KH and GH cannot pass through since they are larger. This neoprene-like material even filters bacteria as well as viruses. RO water therefore is very pure, has no contaminants and has KH=zero and GH=zero. There is no way filtering your tap water through a common household filter can achieve this. The ramification is that your tap water fed through a household filter still most likely has a non-zero KH which will affect the reading you see in the dropchecker. Additionally, the level of acids or bases in the tap water is unaffected by the household filter and these also affect the dropchecker reading. You therefore cannot accurately substitute tap water for RO water in this application. 

Cheers,


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## tennis4you (1 Dec 2008)

Well that's a bummer...  It is still a pretty green


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