PMDD target dosing confusion

[Digitalgerl]

I received my nitrate and phosphate test kits today. I started dosing my 37 g tank 2 weeks ago with Greg Watsons PMDD- 1/4 C of the dry mix was mixed with 500 mls of water and I have been giving the tank aprox 20 mls of this solution daily.
I have been dosing with Flourish for the micros every other day along with Fleets (1/3) teaspoon at the same time.

My Salifert test kit shows phosphate to be "3" - test kit showed this to be "good range"
My Nitrate however appears to be 0
This has got to be why I have had an outbreak of green spot algae.

pH is 7 (out of the tap it's aprox 8.0)
running pressurized CO2 - so I'm guessing 30 ppm

ammonia - 0
nitrites -0
Kh - 5 to 6
gh - medium hardness

Now my question is how do I use this PMDD mix to elevate my nitrate levels?
I understand that once I know how much of the macros my plants are using I can adjust the dosage accordingly - but I am now sure how I reach a target level of 5-10 ppm as quickly as possible.

Should I now back off on the Fleets and when the test shows a drop to "2" I can start adding it back in?
I have tried to use the online dosing calculations but have not had any luck figuring out how to apply this to the PMDD solution..argggggg

Any suggestions would be welcome....

 

[rkilling1]

I would start double dosing your PMDD every other day until you get the NO3's up.

You don't need to be dosing the Flourish anymore. The PMDD has plantex CSM+B in it.

IMO, I would purchase all the ferts seperately and dose accordingly. Using them sperately allows you to use the EI mothod of dosing.

 

[Digitalgerl]

Thanks...I agree that as soon as I use this up (may be before ..lol) I need to purchase seperately. I ordered the PMDD mix because I felt overwhelmed by the information and felt that this would be the easiest way to feed the tank. You're right though, there is no control or fine tuning when it's done like this. AHA! I understand more now..I will lay off the Flourish for now and double dose. Should I test the Nitrates every day? everyother? When I reach my target of 5 ppm then continue with this regimin> or test frequently to see how quickly my tank uses this up and needs to be replenished?

 

[newfound77951]

You'll have to test frequently for a while to get a feel for how fast your tank goes through N and P. If you're keeping you phosphate at 3, then you should shoot for a higher nitrate level than 5 ppm, for a couple of reasons. One, hobby nitrate tests are notoriously inaccurate, and 5 is darn close to zero. If you're measuring 5 it very easily could be closer to 10 (OK) or closer to 0 (Not OK). Two, ideally you want about 5-10x (shoot...now I am second guessing myself here....someone help me out! Maybe it's 2x...at any rate you don't want 3 ppm P and 5 ppm N) more nitrate than phosphate. You may end up needing to dose just nitrate, and use the PMDD for traces (it has some nitrate and potassium but generally not enough of either for most tanks. For me, I don't have to add much more N but I have a lot of fish that eat like little piggies).

I did the same thing you did, got PMDD and thought that would be the easy way....it might work on its own for a very few unique tanks but I ended up having to buy potassium, phosphate and nitrate ferts separately as well.

 

[Digitalgerl]

Thank you for your response! Yes I am going to have to purchase the Nitrates seperately. My lighting is high 130 watts of CF on a 40 gallon tank. My CO2 is good - I measured out of the tank and then measured tap water that I let sit for 24 hours. It showed a 1 point difference. My plants are growing but not as quickly as I would like and there is no pearling. I still am getting some green spot algae also so the tank is not balanced yet.
I have stopped dosing the Fleet until my Phosphate goes down then I will begin to add back. I think I am supposed to aim for Phosphate of aprox 3. Nitrate of aprox 10.
Well back to the drawing board and my check book. lol. It really is interesting isn't it?

 

[Purrbox]

There are many ways of dosing. You can use EI which allows you to dose regularly to ensure there is never a deficiency. You can dose to targets, which requires more testing. And those are just a couple of options. If you go with the targets. It's recommended as a starting point that you aim for 1ppm P to 10-20ppm N ratio. At 3ppm P you'd want to aim for 30-60ppm according to this. Many people (myself included) have found that while you get good growth with this ratio, you may still get GSA which generally indicates low phosphates. As a result, after fine tuning my dosing I ended with a ratio that was closer to 1ppm P to 5-10ppm N, and was dosing around 2-3ppm of P. If you've calibrated your Phosphate Test Kit (tested a reference solution) then I would hold of on dosing P until you start to see a drop in P, if you haven't calibrated the Test Kit I would continue dosing a small amount to ensure that it doesn't bottom out on you. Try to maintain about 2-3ppm of P since this seems to be a natural level for your aqarium, and dose upto 10-30ppm N. Again it's important to Calibrate you Nitrate Test Kit as well, to ensure that you can rely on the numbers.

It took awhile for me to get my head around dosing and all the information surrounding it. I went through several different methods before finally settling on EI and adjusting the levels to fit my aquairum needs. In the process I learned a lot about my plants, fertilizers, algae, and difficiency symptoms. It takes time, but it all starts making sense after awhile and you get to the point where you can start taking care of you plants intuitively.

 

[Digitalgerl]

OK I haven't been dosing for the last few days so I could get a feel for the tank's uptake. I have test kits from Salifert that are supposed to be very good. It appears that my Nitrates are still running about 20 ppm.
But I am confused as to the Phosphate test kit. I think I interpreted it wrong on my first run. The color chart states .03 = good .10 = critical and .25 = (coral growth retarded) 0.50 , 1.00, 3.00 don't state anything. It appears my phosphate was 3. So that is not good correct? And this could be the main cause of the green spot algae?
I understand getting Nitrates up and increasing the plants growth so as to outcompete the algae for available nutrients. BTW plants are growing, not fast but growing and there is no pearling yet. I know my CO2 is aprox 30 ppm. I tested tank water and then water that sat 24 hours. There is a decrease of 1 in pH.
So I did a 50% water change. I tested the tap water and it does NOT appear that the tap has levels of phosphate so it's my fault for dosing the fleets before I had a kit to test with. Phosphate is down to 2. Do I need to do another water change tomorrow morning to try to get it to the 0.03 level?
Any thoughts?

 

[rkilling1]

You should maintain your PO4's between 1 and 2 PPM. That .03 stuff is not for a planted tank.

 

[Digitalgerl]

thank-you, thank-you, thank-you. No wonder we beginners take a step forward and two steps back. There is enough data out there, too much. It is hard to know what data to use and what to disregard. I thought I was going crazy..lol Ok then, I will keep it at 2 and Nitrates at 20, Co2 at 30. Lights on for 10 hours and GSA should subside eventually.
pray for me

 

[Purrbox]

I think I interpreted it wrong on my first run. The color chart states .03 = good .10 = critical and .25 = (coral growth retarded) 0.50 , 1.00, 3.00 don't state anything.

The "Coral Growth Retarded" is a good clue in that the indications are based on SW aquariums. Most manufactures don't seem to realize that those of us with FW Planted tanks are also care about Phosphate levels. In a SW tank the nutrient goals are much different, and Phosphate levels are kept as close to 0 as possible.

Even when you see recommendations for nutrient levels that are geared towards planted tanks, you need to take into consideration when the recommendations were made. Older recommendations are generally based on different dosing strategies than you are likely to be using today. It wasn't that long ago that people still felt that 30ppm of CO2 was dangerous. Always take into consideration the context of the recommendations and determine whether they are consistant with the methods you are using and the your goals for your aquarium.

 

[Digitalgerl]

Well I tested all tank parameters this morning. Phosphate is still at 2. Nitrates are still 20. CO2 is still 30. Ammonia and Nitrite remain at 0.
I don't understand why phosphate and nitrate have not gone down as I haven't dosed for aprox 4 days now. Could it be that my plants are just not using the nutrients effectively for whatever reason. I have 3.5 wpg CF lighting-10 hours a day. Water temp is at 80.
Secondly, if plants use what's necessary and no more does that mean any excess in nutrients are then a catalyst for algae.? I realize our goal is for our plants to out-compete the algae so it can't flourish and stays in check.
I have a 40 gal with 2 anubias, cabomba, 4 jungle vals and 5 cont. vals with many runners. There is also some type of long thin grass (12") and 2 lace java ferns along with a temple plant (Alternanthera).
I have 3 angels, a pictus cat and several platys.
Could it be that my bioload is such that nitrites are converting into nitrates at a rate high enough to feed the plants. I feed fish once a day(either flake, brine or beef heart) and then several drop pellets when lights out (lunars on) for the catfish.
I do weekly water changes of aprox 30%
The plants are growing but not pearling by any means, algae has slowed but is still there.
Any suggestions?

 

[Purrbox]

Give it some time. The only things that happen fast in an aquarium are not good. If the algae growth is slowing you are on the right track. Also the one nutrient that you didn't mention was Potassium. I know that you can't measure it with a testkit, but there also wasn't any mention of whether or not you were dosing it in your most recent post. If there wasn't enough Potassium in the aquarium, that would also hinder the uptake of Phosphate and Nitrate by the plants.

Excess nutrients in general do not cause algae. Just deficiencies. Most often when some reports that they got algae in their tank and there's high levels of such and such, they're missing the fact that another nutrient has bottomed out and is the real cause for the algae AND the climbing levels of the first nutrient. It's not so much that you create an environment that allows the plants to out compete the algae, as you create an environment that favors plants over algae. In a system where deficiencies exist, the algae has a better chance of thriving. There's always going to be some algae in your aquarium, the goal is to keep it manageable and to a point where it isn't noticed.

 

[Digitalgerl]

Ok gotcha...I was using PMDD dry mix I purchased online. There is Potassium in this as of course you know. So I will continue to monitor my tanks uptake of the above mentioned nutrients. I believe I need to buy the ferts seperately so that at some point I can try the EI method. Thanks for your advice. And thanks for explaining that it's not the excess of a nutrient that can cause algae as a general rule but a deficiency somewhere else. The tank is only a few months old so perhaps as things get better established and I continue with good maintanance it will payoff. PS-the fish are fine, I've been the only one stressed. lol.

 

[Jchillin]

PS-the fish are fine, I've been the only one stressed. lol.

That's a positive sign.

 

[newfound77951]

It would be really hard to hurt your fish adding ferts. it is possible, but not likely unless you dump a whole container in there. I know it seems counter-intuitive to ADD the things to your tank that for so long you've been trying to get rid of with filtration, but eventually you'll get used to it!