PMDD question...

[esworp]

Is the Poor Man's Dosing Drops recipie 'out there' a solid 'does everything' fertilizer? i would guess so, since it's got everything but the kitchen sink (co2). I'm hesitant to buy a bottle of trace-this, a bottle of iron-that, a bottle of phosphorus-this, etc etc etc, and consider PMDD a solution to the huge collections of bottles under some friend's tanks.

One good thing about it I would guess is the fact that, say, the potassium is too low in the mix, one could just add more to a fraction of the powdered mixture. With a brand-name bottle, one is less able to 'hack' the contents into something more tuned to a specific tank.

 

[djlen]

I'm a little confused as to exactly how much light you've got over that tank.
But it sounds as if you are relatively new to the planted tank scene and will need to learn the needs of your tank as it develops and changes.
Therefore, rather than getting into the PMDD thing, I suggest that you go here:
www.gregwatson.com/
You really only need KNO3, PO4 and his trace mix. for you purposes at this time, for your tank. Maybe some Mg(Epsom salt) as well.
Then you need to clarify your lighting situation and your future plans with regard to planting etc. so that some of the old heads on the forum can advise you on starting dosages of the above. With your plant mass you will not need a lot of dosing at this time.
The reason I suggest buying the individual ferts. is that, IMO one needs to tinker with dosages and learn what grows plants and not algae, before settling on a set mixture of nutrients.
I've been into planted tanks for a bunch of years and still tweak so much that it makes no sense for me to mix up(or buy) a large batch of anything. My tanks are constantly changing and so are their needs. And it's really very easy to establish a routine for dosing the above elements individually.

Len

 

[esworp]

I'm a little confused as to exactly how much light you've got over that tank.an getting into the PMDD thing, I suggest that you go here:
www.gregwatson.com/
You really only need KNO3, PO4 and his trace mix. for you purposes at this time, for your tank. Maybe some Mg(Epsom salt) as well.


The reason I suggest buying the individual ferts. is that, IMO one needs to tinker with dosages and learn what grows plants and not algae, before settling on a set mixture of nutrients.
Len

My hopes were to use the pmdd as a baseline to start with.. get the raw materials to make the by-the-book recipie, and make little batches to facilitate tweaking/hacking - just lke you recommended.

As for lighting, I'm at 4.45wpg, if you ignore the led arrays I'm experimenting with (they're only focused on one plant/corner).

 

[djlen]

OK, at that wattage and with CO2 you will need to start dosing soon, but with a light plant mass it will not have to be heavy. You may have to add floaters to shade the tank until you get some more mass in there with that wattage.
My suggestion is to get the elements and then download the desktop calculator from Chuck's website. This will give you ballpark numbers for beginning dosages. I would halve the dosages recommended and increase as you see an increase in mass and the plants tell you they need more nutrients.
PMDD is, again IMO, really pretty much a thing of the past. More and more people are dosing individual ferts. and changing while they learn the tank as time goes on.
You can make up a batch of ferts. based on what the calculator calls for if you want to, but as mentioned before, it's really very easy to dose individually, after water changes and again at mid-week if necessary.
What kind of pH/kH relationship are you experiencing? Just trying to get a handle on how effective your DIY CO2 is for you.

Len