PMDD vs EI

[dapellegrini]

Ok, I think I am thorougly confused again. I purchased and have dosed out 250ml of PMDD. Actually biught CSM+B, KNO3, MgSO4 and K2SO4 and mixed the amounts indicated on Greg Watsons website. I quickly learned that my formula did nothing for my nitrate level so I have also been supplimenting KNO3 directly (premixing in some tank water 1tsp 2x a week).

Now I am reading about the EI and am considering mixing and dosing macros seperately, but I am a bit confused about the two different methods. Apparently with EI, I am not dosing MgSO4, and instead dosing KH2PO4 (Phosphates)... Since my phosphates are already really high, I don't mind leaving that out of the equation. Why no more Magnesium Sulfate in EI?

I am dosing into 72g - which I am considering 60g for dosing purposes.

So EI says:

60 – 80 Gallon Aquariums
+/- 3/4 tsp KN03 3x a week
+/- 3/16 tsp KH2P04 3x a week
+/- 1/4 tsp K2S04 3x a week
+/- ¼ tsp (15ml) Trace 3x a week
50% weekly water change

If I want to mix into 8oz of water and dose out in 1/2oz doses 3x a week, I am looking at a 16x multiplier on each of these ingredients. Any problems leaving the phospate out? And again, what do I do with my Epsom Salt MgSO4?

TIA

 

[rkilling1]

what is your PO4 level?

what is your GH level?

 

[rich311k]

I would just dose everything dry seperately. I would add the phosphate as well. Since it is in your tap maybe add it twice instead of three times. It is easier to make solutions for the traces and phosphates. Add enough traces to get your iron to .1 to .2 ppm. This web site justanothertank.com has a calculator for mixing traces. After two or three weeks see how your plants and any algae growth is going and adjust accordingly. Good luck and have fun.

 

[dapellegrini]

My PO4 are off the charts on my Hagen test. +5.0mg/L, my GH is also very high (I have tried upto 75% water changes to no avail). I can't add enough drops to my Aquarium Pharaceuticals GH test to get it so change color, i.e. either off the charts or a bad kit (but I have two and they both do the same thing). My kH is around 6, which I think figures out to 110ppm or so. CO2 injection in a tap water that is ~7.8, bringing it down to 6.9, so 22.7ppm of CO2 per Chuck's calculator.

 

[rkilling1]

with a GH that high i wouldn't worry about not dosing MgSO4. I agree with rich on just dosing PO4's maybe twice a week instead of three times. It's better to overdose then to run out.

 

[Purrbox]

Even though your PO4 is high now, keep an eye on it. Once you get your dosing balanced out you may suddenly find that you need to start dosing it.

 

[dapellegrini]

For whatever reason I didn't realize the the Epsom Salt was for GH.... I don't have any PO4, and I have never dosed it. Seems between fish and fish food I can never get it under the 5mg/L measure of my test kit. I guess perhaps I should order some...

 

[Zezmo]

Your question, why no Mg in EI?
The simple answer is, that EI does not dictate which exact fert you use. EI is instead a technique where you provide an excess amount of any needed nutrient and prevent buildup by doing 50% weekly water changes (or more or more often).
The typical pattern for EI is Macros 3 days a week, every other day, and micros 3 days a week on different days from the macros.

To answer your question more directly, is that if you need Mg, them add it, regardless of how you choose to fertilize. This is true of all ferts. In EI you start with a "standard" amount of ferts, but you will have to adjust up or down, based on your setup and tanks needs.

 

[dapellegrini]

Thanks Zezmo.

So another potentially stupid question: why the discrepancies in the PMDD formula and the EI? I guess to answer my own question, two different sources. Is the idea of PMDD to try and maintain a correct level, opposed to EI which overdoses and flushes weekly?

 

[Purrbox]

The differences stem from the fact that they are two different dosing methods based on two separate dosing philosophies. PMDD are based on the idea that excess Phosphates will cause algae and provide a set ratio of nutrients. EI was developed later, when further research showed that excess nutrients (including Phosphates) don't actually cause algae, only nutrient deficiencies. The idea with EI is to dose enough of all the nutrients to ensure that none ever bottom out, and to use a large water change once a week to keep levels in check and safe for the tank inhabitants.

 

[Plantbrain]

You are not "overdosing" either.
Folks like certain buzz words, and this leads them to prejudices that have no foundation.

You are maintaining a "set range of nutrients", the kind that grow plants best.
You are providing non limiting levels of nutrients.
This maxmizes light efficacy, so light is the only thing limiting growth.
That's ideal and main driver of energy and growth in the system.

Most everyone flushes that uses CO2 etc, we call it a water change.
I just took it further for a few reasons.
EI removes the uncertainty of test kits.
It's easy.

You may want to re read the EI, I do account for GH, both Ca and Mg.
You can add the GH booster(also available from Greg at a much less cost than the SEaChem Equilibrium) abd add about 1-2 degree's worth after a water change.
Some just add epsom salt, say 1/4 teaspoon 2x a week for a 20 gal tank etc or a bit at the water change only.

Want more accuracy and even less potential builld up?
Do 75% weekly water change.
Or 50% 2x a week.

A simple water change is a very useful tool and helps both fish only, marine and Brackish tanks very well.

Regards,
Tom Barr

 

[dapellegrini]

Thanks Tom. I appreciate your feedback. I am slowly figuring all of this out.

My current PWC routine takes the water down to the max without breaking the canister suction... I am guessing that's around 60% or so for me....

 

[Plantbrain]

Then 50% is fine, you can do 2x a week if paranoid, or weekly is fine, after awhile, many get lazy and do 2 week 50% unless they wanna whip the tank into shape for photo's, open houses etc.

After awhile, it's really very easy and becomes "old hat".
As you gain more comfoprt and experience, it becomes very easy to spot what you might be doing wrong and we all negelect tanks over time for some time frame, then we know what to do and what things look like.

Generally, the biggest issue is CO2 when you reduce the limitations from nutrients as EI does.

Light is then the only limiting issue for plant growth.
EI isolates the CO2 effectively for most every light level anyone might have.

So that is the only variable left.

That makes any lull in plant growth, algae etc an easy fix.
It also shows how many things go wrong that are CO2 related.

If you account for and isolate the issues with nutrients, then all that is left is CO2.......

Less light=> less CO2 demand, more light=> CO2 demand and so on........

It's not a tough concept really.
Myths, LFS's advice and general fear mongering has caused a lot of grief in the hobby and made a lot of $$ for Aquaschisters.

The entire EI article is in about 12 languages now.
The Aquatic Gardener (TAG) has the article in print as well

Not a bad organization to join (the AGA).

Local plant clubs are sprouting and are a good resource also.

Regards,
Tom Barr

 

[fish_4_all]

EI dosing and measuring each one seperately is well worth it. I switched to it and yes I have had my minor problems with algae but I have never had an "outbreak". One thing to remember with EI that I didn't understand was the CO2 requirements. Make sure you have a steady supply and fairly constant levels and you will be well on your way to a happy planted tank and healthy fish. High light and EI dosing almost mandates 30ppm+ CO2 but is a lot harder to maintain with DIY CO2 than it was before I started EI dosing. Before EI I had green spot algae and some soft filament type algae, never anything worse. Now I fight my minor battles with BBA and string algae but it is manageable to the point that I dont have to remove leaves more than twice a month and I remove little string algae as it tends to collect in one spot and is easier to remove when it gets longer or the leaves it is on are ready to be removed.

Well worth not having to test if you ask me, especially if you are just color blind enough that you can't tell the difference between most of the test colors. Like me.

Ask Mr. Barr, I was as big a skeptic, and kinda still am, as you will find even after it works to some degree. That said, I will keep using it until I either master it or I find something that works better.

I dose everything, even MgSO4 at the rate of 1/4 tsp once a week right after my water changes. I plan to get Gregs GH boost once I have the money or finding Calcium Chloride or Calcium Carbonate locally. Right now I use Calcium Citrate but it has messed with my KH so I need something that won't, probably the calcium chloride.