• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

PMDD

T

tennis4you

Member
Joined
7 Jul 2008
Messages
137
Location
USA
I finally received my PMDD in the mail yesterday. The dosing for it was recommended to me such that:

1/4 cup of powder to 500 mL of water. Then 1 drop per gallon of water per day. You could go 2+ drops per day, but seeing that my CO2 tank is not here yet and I am just learning I will start with 1 drop per gallon per day and see where that takes me.

But with that being said, is any of that assuming I do any specific water changes per week or something? Anyone lese use PMDD?

Thanks!!!
 
JamesC discusses the technique of PMDD style dosing on his webpage PMDD - Poor Man's Dosing Drops

Not injecting CO2 while using high lighting in a new tank setup is just asking for trouble and will typically take you to algae hell. Therefore keep the lighting low until the CO2 equipment arrives. Water changes are a function of CO2 addition so I think it would be better to follow the non-injected technique of low lights and no water changes until CO2 injection is sorted out.

Cheers,
 
Thanks! One question though.

The dosing said:

2 ml of Macros solution per 10 gallons (US) or 40 litres
1 ml of Micros solution per 10 gallons (US) or 40 litres
Click to expand...

But isn't PMDD both micros and macros?
 
Those amounts are for the PMDD + PO4 dosing that I use. The original PMDD didn't have any PO4 added so the micros could be added to the macros without any problems. But due to possible reactions between PO4 and an iron in the micros the two solutions are kept seperate.

James
 
You said that the original had no PO4 but it sounds like in your last sentence it still doesn't?

Thanks!!!
 
That's correct. PMDD has no PO4. I have modified the formula and added PO4 to it which I call 'PMDD + PO4'. The term PMDD has now often come to mean dosing with dry ferts or solutions made from the dry ferts, so it can seem quite confusing at times.

James
 
JamesC said:
That's correct. PMDD has no PO4. I have modified the formula and added PO4 to it which I call 'PMDD + PO4'. The term PMDD has now often come to mean dosing with dry ferts or solutions made from the dry ferts, so it can seem quite confusing at times.

James
Click to expand...

Interesting, I thought PMDD covered it all. So I need to hunt down some PO4. Any recommendations in the States?

I ordered this:

PMDD Pre-Mix 1 lb contains 1 part each of Potassium Nitrate, Potassium Sulfate, Magnesium Sulfate, Plantex CSM+B.

Does PO4 = Phosphates? Maybe one that is not contained in the PMDD Pre-Mix?
 
Yep, PO4 is phosphate and the mix you quote doesn't contain any. I would dose some potassium phosphate as well as plants require PO4 to grow, but don't add it directly to your mix as it may react. When PMDD was formulated it was thought that PO4 was a cause of algae, but this has now been shown to be incorrect.

Potassium phosphate from here - "http://www.aquariumfertilizer.com/Store.php"

James
 
OK, I just ordered the Mono Potassium Phosphate so I can dose with that along with the PMDD. I am currently dosing with PMDD with 1 drop per gallon in a 125 gallon tank.

Knowing that I am dosing PMDD with 1 drop per gallon, what is the recommended dosing for the Mono Potassium Phosphate?

Thanks (again) guys!!!
 
Why not just modify your existing solution by throwing in some KH2PO4 amounts James has listed on his webpage? You don't have to be accurate, just in the ballpark.

Cheers,
 
ceg4048 said:
Why not just modify your existing solution by throwing in some KH2PO4 amounts James has listed on his webpage? You don't have to be accurate, just in the ballpark.

Cheers,
Click to expand...

James said not to mix them in his post above. 🙂
 
The mix you stated above looks like an all in one mix including the traces/micros (CSM+B) which will include the iron. Therefore what James is suggesting is to make a seperate mix of the KH2PO4 (Mono Potassium Phosphate) and add this at the same time but from seperate solutions/dry powders.

You can make a solution with the ingredients you have and just throw a small pinch of the KH2PO4 powder in weekly or go by the dosing strategys and measure more exact amounts. I think if doing it dry then it would be hard to measure daily amounts of this.

This is why I always make mine into solutions which dilutes the main ingredient. therefore 1ml of a solution is easy enough to measure via a syringe. To measure out the amount of this ingredient dry would amount to counting grains in some cases.lol

p.s. I also use this PMDD+PO4 mix and dose 4ml macros and 2ml micros under low light with CO2 injection

AC
 
SuperColey1 said:
The mix you stated above looks like an all in one mix including the traces/micros (CSM+B) which will include the iron. Therefore what James is suggesting is to make a seperate mix of the KH2PO4 (Mono Potassium Phosphate) and add this at the same time but from seperate solutions/dry powders.

You can make a solution with the ingredients you have and just throw a small pinch of the KH2PO4 powder in weekly or go by the dosing strategys and measure more exact amounts. I think if doing it dry then it would be hard to measure daily amounts of this.

This is why I always make mine into solutions which dilutes the main ingredient. therefore 1ml of a solution is easy enough to measure via a syringe. To measure out the amount of this ingredient dry would amount to counting grains in some cases.lol

p.s. I also use this PMDD+PO4 mix and dose 4ml macros and 2ml micros under low light with CO2 injection

AC
Click to expand...

So are you saying you dose twice the amount of the PO4 mix as you do the PMDD? Did I track with that right, not sure I did.

PMDD = Micros???
PO4 = Macros???

I am the same as you, low light (1.2 watts per gallon in a 125 gallon) and CO2.
 
PO4 is one of the macros - NPK
micros is trace- your CSM+B

I have the KH2PO4 in my macro solution along with the KNO3 (pot nit), K2SO4 (Pot Sulph) and MG2SO4 (Mag Sulph).

I then have a micro/trace solution which is basically the same as your CSM+B in another solution.

I order all my ingredients for the macro solution seperately and then weigh them out as per JamesCs measurements. The trace mix is already mixed so all I do is add the DI water.

My 4ml and 2ml is an excess slightly if you equate it to JamesCs lighting. I have approx one third of his lighting but dose two thirds of his fertiliser. This slight excess is no problem though and allows for me forgetting a day here or there.

If all your powders are pre mixed I would find out how much of each is in the pre mix and then work from the lowest one how much in ml to use. i.e. if all your ingredients were equal proportion to James apart from 1 then calculate the dosing from that one. It will dose excess of the rest but that shouldnt matter. Better to have excess nutrient than to be defficient.

AC
 
Alan at Aquarium Fertilizer.com has been answering some questions for me as I ordered the PMDD and then the KH2PO4 as well. But he gave me different feedback and I am looking for clarify. Now please keep in mind, I am not trying to throw anything bad in the mix or rip on anyone, shoot, I may not have been clear with him at all for all I know. Here is his response. Any thoughts? He is recommended as a newbie I stay away from the KH2PO4 that I ordered...

I guess my real question is, "Why are you adding phosphate?" If you haven't yet done so then I recommend you read about the whole PMDD concept at thekrib.com/PMDD. As a self-proclaimed novice you may not yet be aware that there is not one primary goal in fertilizing your planted tank, but actually two. One is obvious; promoting the growth of your treasured plants. But the second is at least as important; discouraging the growth of the many types of algae that are always present in your tank just waiting to take over. Adding MKP without careful controls and testing is a surefire way to achieve explosive growth of algae. I recommend that you STOP. Learn about the signs and symptoms of potassium deficiency, and get a test kit, before deciding to add MKP again.

Most "novice" aquatic plant enthusiasts don't start with a bare tank and plants. Most start with a fish tank and plants. Most people with fish feed those fish. All fish food is packed full of phosphates. Usually the novice's problem is too much phosphate, not too little.
Click to expand...

I was basically asking about the amount of recommended dosing solution. Not sure what "MKP" is but I assume is is the Phosphate I ordered. I have it now, but I have not yet started dosing it. Still trying to figure out what to do and what all is best.

Any feedback would be great. His response makes sense, but I was told here to dose some with it so I am under the assumption that it will be necessary.

Thanks!
 
Alan is of the old school of thinking. Even the people who initially developed the PMDD theory of phosphate being the cause of algae now concede they were wrong. His final statement is the wrong way round. It should read "most noveices problem is too little phosphate as they beleive what the old school taught them r.e. phosphates causing algae"

Alan will be of the thinking that excess nutrients cause algae. The true fact is that you can add 20x the mount of nutrient that plants need and as long as the plants are not defficient then algae will not occur.

What we currently understand to be the trigger for algae is ammonia which is leeched by plants when they get damaged. This is why you see a plant that is damaged that has algae on it. Most people assume that the algae has caused the deterioration of the leaf when in fact the plant damage may have been unnoticeable which then leaked ammonia which then triggered the algae and by the time the damage was visible the algae was quite well established.

CO2 is more important also along with very good circulation as this is often the cause of algae in that CO2 is great in certain areas but the circulation is not distributing the CO2 very well around the whole tank. therefore you get some plants doing great and others that get covered with localised algae.

If you take an EI tank for example This regime means that you are adding a large excess of every nutrient. The plants therefore always have a source of all the nutrients and if Alans theory was right then this regime would not be for novices. Quite the contrary, EI is probably the best regime to start on and many continue with it. Once you are happy with the EI setup then you could move onto something that lets you start decreasing nutrient amounts, so you see that I and most of the others on here are suggesting the exact opposite to Alan.

If I were you I would read up the EI sticky and the PMDD+PO4 sticky and get a grasp of what we, Tom Barr, and many many others now use and understand r.e. algae and its triggers etc. Then you can give Alan the links too. lol

Hope that clears it up. not ranting, just want to clarify the old thinking to the new.

AC
 
Thanks AC... SO let me throw this at you.

I read this from the PMDD website link:

PO4 Modified PMDD Formula

This PMDD formula is based on the latest formula found on the Krib website but with the addition of potassium phosphate. In the original formulations all of the ingredients are mixed into a single solution, but this is no longer possible due to the potassium phosphate which will react with any free iron. It is therefore necessary to make up two separate solutions for macro's and micro's.

Macros
17g Potassium Nitrate
1.5g Potassium Phosphate (monobasic)
18g Potassium Sulphate
20g Magnesium Sulphate Heptahydrate (Epsom Salts)
500 ml distilled water

Micros
15g Chelated Trace Element Mix (7% Fe, 1.3% B, 2% Mn, 0.06% Mo, 0.4% Zn, 0.1% Cu)
250 ml distilled water
0.5 ml Normal Hydrochloric Acid


Dosing

The level of dosing is dependant on your plant stocking level. The amounts below are designed for a fully planted tank so if you are 50% planted then you can half the amounts. These are the amounts that I use on my tank and that I know work for me. They are both dosed on a daily basis.

2 ml of Macros solution per 10 gallons (US) or 40 litres
1 ml of Micros solution per 10 gallons (US) or 40 litres
Click to expand...

So I bought Mono Potassium Phosphate. But according to the Macro solution mix I am missing 3 other ingredients? I am of course using PMDD for Micros? Or do I just need the Mono Potassium Phosphate? If it is all I need, how much do I dose? It seems like I need more ingredients and then I will know how much to dose per the recommendations above. Looks like I dose twice the amount of Macros as I do PMDD?
 
All you have to do is dose the Potassium phosphate separately as the others are in your PMDD mix according to its recipe. You'll just have to add the phosphate from a separate tub as it'll cause the iron to precipitate if it's mixed together. You can still dose them on the same day (I do) as once they're in your tank in a large volume of water they will have dispersed a lot, it's just when they're kept in concentrated solutions that serious problems seem to occur.
 
Do you know what the content of your PMDD mix is? What was advertised?

Seems strange to me that someone is selling a premixed PMDD powder because PMDD would contain the 3 other missing ingredients and trace elements. In which case you would never be overly sure how much of each you were dosing each day.

My guess however is that the powder you got contains everything that is in JamesCs recipe (minus the PO4) macros and micros as this was the original PMDD. therefore your solutions will be slightly different to JamesCs in that you will have 1 bottle with most of the ingredients in it and then a supplementray seperate solution with the PO4 in it.

I would suggest that next time you buy powders it would be easier for you and more useful too for you to buy all the seperate ingredients yourself and then you can be sure of the amounts you have in your solutions. It will also allow for a little tinkering if you want to reduce or increase anything within the solution.

AC
 
This is what came in the PMDD:

PMDD Pre-Mix 1 lb contains 1 part each of Potassium Nitrate, Potassium Sulfate, Magnesium Sulfate, Plantex CSM+B.

So with that said, how will I know how much of the PO4 to dose?

Thanks!!!
 
You must log in or register to reply here.
Back
Top