Anyone doing PMDD?

[justDIY]

ok...... I've read a LOT about mixing your own PMDD.... but I've never tried to cook myself up a batch

The last bottle of fluorish I bought cost me $10 and looks like it will last my 29 and 30 gallon tanks a LONG time, as the dosage is about 1 ml each a week and it's like a 1 liter bottle.

however, I am hoping to setup a 120 gallon planted tank soon, and that would clearly require larger doses.

I've also read, but don't clearly understand, that mixing your own PMDD allows you to talior your nutriants better to what you need, rather than a blanket dose like flourish or flourish+iron.

The only metal test I have is for Fe - I haven't looked too closely for any other metal tests (like K or Mg) or mineral tests like phosphates.

Once I start reading a "simple" PMDD recipe, my eyes glaze over when they talk about ordering this and that from your pharmicist or buying a bag of green lantern stump remover for some chemical it has...

I realized the problem - these articles contain too much theory and "padding" to absolve the author from some sort of (preceived liability?), as well as to generalize the procedure to work for a large range of conditions.

Can anyone share their first-hand, practical knowledge about making your own fertilizer mix?

TIA!
Gordon

 

[Guest]

I don't use PMDD, but I do dose dry bulk nutrients. The problem with PMDD is that it's a one size fits all solution and IMHO it doesn't fit that many. Also I feel that the basic premise behind the original idea of PMDD, controlling algae by limiting phosphates in the tank, have been soundly disproved. I have written a long article on another forum about the use of PMDD, and the reasons not to use it.

As far as test kits go. Don't bother testing for iron. The first problem is that consumer level iron test kits are not very reliable. Second thing is in your case you aren't dosing enough iron to worry about it. Flourish is a great product and I do still use it. But on my 2 wpg 29 gallon tank I'm dosing around 10 ml a week. On my 4 wpg 55 gallon tank I dose closer to 40-50 ml a week. I love Flourish for the traces it contains. But I also dose iron, a more concentrated trace mix, potassium, and nitrates and phosphates as needed.

That reminds me. The PMDD formula doesn't have near enough potassium in it.

How much light are you planning on using on your 120 gallon? And just for general info I have sold over 200 lbs of bulk dry nutrients and over 50 lbs of trace mineral mix in the past six months or so. I'm not a retailer, or a store, just a hobbyist that helps other hobbyists.

 

[justDIY]

I'm looking at intially running a 250 watt MH 12 hrs, and maybe supplimenting 4 or so hours with a pair of 96 watt PC's... eventually when the budget allows, I'll add a second MH and disband the PC's

I wanted to start off low and work up to a "high light" enviroment, as the plants establish themselves.

I also have a high pressure CO2 system on stand-by, with a PH controller.

10 ml a week on a 29... wow - please explain how you came up with the dosages?

I was following the bottle's claim of 1 ml per 50 gallons twice a week, so I was dosing 1/2 ml every 3 days.

thanks for debunking the PMDD mystery ... I'd be interested to hear more about your dry mix though!

 

[Guest]

Hmm.... if your 120 gallon is a standard 6' tank then one or even two MH lights are not going to give good coverage. Normally you figure that a MH light will cover a 2'x2' area. If I were you I would either settle on PC or MH lights and just stick with them. As for ramping up the light I'm not a big fan of that. I prefer to start with at least 3 wpg so I can do a silent cycle. The majority of stem plants that one uses in a silent cycle do best in higher light. And believe me they establish pretty quick. When I set up my 55 gallon tank I trimmed out over two gallons of stem plants within two weeks.

As for my Flourish dosing. I just go with what gives me good plant growth. I dose 5 ml twice a week in that tank and even with 2 wpg the plant growth is very good.

The dry trace mineral mix I use is Plantex CSM with boron added.

 

[justDIY]

Hmm.... if your 120 gallon is a standard 6' tank then one or even two MH lights are not going to give good coverage. Normally you figure that a MH light will cover a 2'x2' area.

the tank measures 48x24x24 ... I'd like the 125 which is longer but not as wide or tall, but it won't fit in the space that I've "set aside" for the tank.

my idea is to build a 'tall' canopy and have the MH mounted over the center of the tank and then the two PC's mount on either side of the MH.

250 + 192 = 442 watts ... of course, some is lost, but that would be around 3 watts/gallon... I agree that the lighting won't be even, but perhaps I can have a high-light swords toward the center where they get MH and PC, and off to the sides more moderate light plants.

I will look into the budget to see if another MH is possible, it would be good to get everything out of the way up front.

Speaking of lights - have you experiemented with normal output bulbs on a vho ballast? I have at least 10 NO bulbs 8 t8's and 2 t12's, which are in the 5000k and 6500k. I'm trying to think of a good way to "use them up".

-----

I plan as you mention, to use fast growing stem plants initially in the main tank, and as it settles in, I plan to move the more hardy varities (anacharis mainly) to a chamber in my sump, where they will be lit opposite the main tank, to provide additional oxygenation and waste product removal. Does this sound plausible, or just like a waste of time and energy?

Thanks for all your feedback!

Gordon

 

[Guest]

I have never used NO bulbs on a VHO ballast. But I can tell you it would "use them up" pretty quick

You could place the other plants in your sump but then you would also have to provide lights there also.

 

[Guest]

Speaking of lights - have you experiemented with normal output bulbs on a vho ballast?

Yes I have. It does use them up pretty quick, and they seem to generate more heat than the vho bulbs.

I plan as you mention, to use fast growing stem plants initially in the main tank, and as it settles in, I plan to move the more hardy varities (anacharis mainly) to a chamber in my sump, where they will be lit opposite the main tank, to provide additional oxygenation and waste product removal. Does this sound plausible, or just like a waste of time and energy?

Basically a freshwater refugium, minus the copepods and stuff. Worth a try if you feel like it, but not sure there would be much advantage to it, since your main tank will be planted also.

I have considered doing something like that for, say, an Oscar tank. Oscars would never tolerate real plants in their tank, but a fuge could seriously help with water quality there, at least that's my theory.