Nitrate Levels?

[fishquiz]

The Krib suggestions for measuring correct dosing of PMDD are to monitor the iron levels. Plantbrain has suggested that he believes that nitrate is the key to controlling algae.

Is there a target level of nitrate I should look for in dosing PMDD?

Thanks

Lee

 

[Richer]

I also believe that in a heavily planted, high light setup nitrates is the key to preventing algae outbreaks. You usually want to keep your nitrates at around 5-10ppm.
PMDD is slightly outdated and needs to be revised a little. In general, the purphose of PMDD is to limit algae outbreaks via control of phosphate (thats why there is probably no mention of phosphate dosing in a PMDD recipi your looking at). This of course isn't true. Tom Barr has had tanks with high phosphate levels with no algae outbreaks. Ammonia seems to be the trigger for algae outbreaks.
For reference, currently on my 70 gallon tank, I dose with enough KNO3 to achieve a level of 5-10ppm. 3-4 capful of Seachem's pottassium once a week (after a 40% water change). 3-4 capful of Seachem's fluorish trace every 2-3 days. I'm currently pondering the benefits of added phosphate dosing.. my tap water seems to contain enough of it.

HTH
-Richer

 

[plantbrain]

PMDD is an all in one mix.
It uses Iron levels as the proxy for setting the amount to be added or some folks watch the NO3 instead.

Neither method is good IMO, since it relies on two of the most problematic test kits in planted tanks that are often unreliable unless you want to pay a good deal for Lamott NO3 test kit. I have no iron test kit I care to suggest for a number of reasons.

You can add the ingredients individually easy enough.
Mix the Trace mix in a bottle with 2 Tablespoons in 500mls of water.
Use that for your "Traces". I add SeaChem's Flourish along with this at 1:3 ratio to get the Boron and some other minuet metals etc in there that are lacking in the CMS/Platex mixes.

The KNO3 and K2SO4 are easy enough to add.
You can control your NO3 pretty well if you know what your Tap water has in it(Ask them for PO4 and NO3 levels from the tap).

You only have 4 things to mess with.
Traces
KNO3
K2SO4
NaH2PO4, or KH2PO4
All these are added once a week, the K2SO4 is added after a weekly 50% water change only, the others are add to suit, most often about 1-2 more times before the next weekly 50% water change.

Each water changes "re sets" the tank and corrects for any dosing errors builds ups or deficiencies.
So you can come very close to your targets without test kits.

Keeping the CO2 and light in good shape is the other part.

The rest is pruning, adding algae eaters and regular mainteance etc.

Regards,
Tom Barr

 

[99RedSi]

Is a week long enough for the plants to use all of the nutrients you've added to the tank? I would think changing the water once a week would negate the addition of all of the nutrients. How quickly do plants *consume* the nutrients you add after a 50% (or whatever) water change?

 

[plantbrain]

With good light, CO2, high density fully planted tanks, Keeping the nutrients with a good range requires 2 more doses typically during the week before the next water change. Plants gobble it up.

You do not want the plants to be left with no nutrients in the water coilumn for more than 1-2 days max with good light(2w/gal or more)/CO2.

You also don't want too much so adding it only once a week will add too much.
Some folks can get some of the nutrients from fish waste, but often that's not enough or not in the right proportions. Some folks get lucky with that, and their tap water has PO4 so they never need to add much of that etc.

If you add a bit too much or too little, the weekly water change re set corrects for that.

The Dutch had a load of of NO3 and PO4 in their water so adding TMG(traces with high K+) , good CO2, light made their tanks grow well.

Regards,
Tom Barr

 

[fishquiz]

Thanks - great feedback

Tom - unless I somehow I missed it, you didn't say how to dose the trace mix, KNO3 and the K2SO4. How much per gallon? You stated that it can be controlled, but what am am I shooting for?

What is NaH2PO4 and KH2PO4? Any common sources?

Thanks again

Lee Hollis

 

[plantbrain]

NaH2PO4= Sodium phosphate
You can get this in the form of a Fleet enema. at the drug store etc

KH2PO4- monobasic potassium phophate
You can get this at at www.litemanu.com

These add PO4.

I add KNO3 at the amount of 1/4 teaspoon per 20 gallons, this yeilds about 10-11ppm of NO3 extra added.

A good range of NO3, 5-10ppm

K+ is add also added with the KNO3, about 7ppm is added for that part of K.

K2SO4 tops this off to the 20-30ppm or so range.
Again, 1/4 teaspoon per 20 gallons but only add this after a weekly 50% water change.

Add the traces at 5mls per 20-30 gallons.

It's just like cooking.

Regards,
Tom Barr

 

[fishquiz]

Thanks

Lee