Dosing of liquid fertilizer

[valice]

When dosing of liquid fertilizers, there is an "optimum" level which we wanna achieve according to Tom Barr's EI method.

I understand from the threads that I read that we wanna have
5-20 ppm of Nitrate
1-2 ppm of Phosphate
20-25 ppm of Potassium

So, each time when I dose, should I dose those amounts or should it be spread over a week?

Please correct me if I am wrong regarding the numbers. Thanx.

[|squee|]

I dose those amounts each time I fertilise, which is about 3 times a week depending on your tank's individual growth rates and needs. I also target the middle range of the above ranges, like 10ppm of nitrate, 25ppm of potassium. For phosphate, I think I've always been dosing about 4-5 ppm. I've not seen spot algae for a long time.

[Phillipians]

hi there, dont worry higher phosphate wont get you any algae as tom barr has himself explained and proven. There is no prob in dosing 15 - 20 ppm nitrate too, and 25 PPM of potassium like squee is doing is a good level to keep at.

I dose my tank 3 times a week too, cause mine is almost 5 WPG thus i ll need to dose more. It really depends on your tank specs and also the plants you are keeping. Some take in nutrients faster, others are moderately fast others are slow. Also higher lighting means you ll need to dose more and also add more co2 as well Maintain a good level of co2, thats most impt

[rosha]

Hello bro,

In my case I put 2 cap of liquid fertilizers, 2 cap of iron every day and I mantain a good level of CO2 because I turn on the light for about 16 hours a day. I don't think so much about potassium, phosphate and Nitrate as long my tank never grown any algae and the plants grown well.

[valice]

I don't really have much of an algae problem too, except for some specs of BBA as a result of forgetting to change my DIY CO2. Now converted to pressurised cylinder already, so hopefully won't have BBA problem again.

I'm currently only dosing like ~10ml of Seachem NPK and 1 ml of fluorish 3x a week and quite some ferrotabs ard the rooted plants in the substrate. Getting some green spot algae here and there... so wondering how you guys fertilise here...

[|squee|]

Up the dose to 15ml if I were you. More phosphate = less green spot algae ime.

[PeterGwee]

1-2ppm per dose should be more than enough whereas the frequency depends on the light intensity. Its never an issue to have excess nutrients. If the rest of the nutrients are in good shape, up the CO2 slowly.

Regards
Peter Gwee

[valice]

1-2ppm per dose should be more than enough whereas the frequency depends on the light intensity.

1-2ppm per dose of phosphate?

i have 55W for a 2ft tank and ~2bps of co2, so is 3x a week good?
kH: 7
ph: 6.8

[|squee|]

Imho, yes 3x a week is good.

[eyalco]

I understand from the threads that I read that we wanna have
5-20 ppm of Nitrate
1-2 ppm of Phosphate
20-25 ppm of Potassium

I'd change NO3 to 10 ppm minimum, as most of our test kits aren't correct, thus we might have 0 NO3 instead of 5 and not know it.

On K, I think it can be a little wider, till 40 ppm or so.

[spinex]

Valice,

I'm also new to dosing based on EI. So also as confused as you when reading the recommended dosing by Tom Barr

CO2 range 25-35ppm
NO3 range 5-30ppm
K+ range 10-30ppm
PO4 range 1.0-3.0 ppm
Fe 0.2-0.5ppm or higher (?)
GH range 3 degrees ~ 50ppm or higher

But if you take a look at one of his example on "A Typical Dosing Routine"

A Typical Tank
A typical routine for a high light tank with low fish load:
Volume 80 liters (20 gal high standard tank)
5.5 watts/ gal. - two 55watt 5000K/8800K lamps
CO2-25-30ppm (I turn my CO2 off at night)
Canister filter
Fluorite (any porous iron rich material will do) about 7-10cm depth

A Typical Dosing Routine
1/4 teaspoon of KNO3 3-4x a week (every other day)
1/16th-1/32nd teaspoon of KH2PO4 3-4x a week (every other day)
Traces added on off days as the macro nutrients, so 3x a week, 5mls each time.
SeaChem Equilibrium 1/8 teaspoon after water change.

Based on the above information (assuming you dose every other day). Also 1/24th teaspoon of KH2PO4 as example. Below is calculation of PPM based on Chuck's Planted Aquarium Calculator :

For 80 litre of water per day is roughly:
2.9ppm K
4.9ppm NO3
0.96ppm PO4

For 80 litre of water per week is roughly:
20.3ppm K
34.3ppm NO3
6.72ppm PO4

This is more or less in line in what Tom Barr has also mentioned in his EI
Some Typical uptake rates at high light and CO2 levels per day (24 hours):

NO3 1-4ppm
NH4 0.1-0.6ppm (do not dose NH4! It will cause algae)
PO4 0.2-0.6ppm

If anyone feel my calculation is misleading or incorrect feel free to comment. Afterall i'm a newbie

[solonavi]

Pardon me but I need to ask this, will having base fert have any effect on liquid fert dosage routine?

Thanks
JC

[spinex]

Pardon me but I need to ask this, will having base fert have any effect on liquid fert dosage routine?

Thanks
JC

I think unless most of your plants are stem plants or else best to add on using liquid fert. Maybe you would like to dose on the lower end base on EI index for a start.

I used to have a Nano tank with base fert (lots of it) but plants grow better with liquid fert added from what i experience.

[solonavi]

Cool! Actually most of my plants are stem based but wanted to dose liquid fert also cos I read that plants absopt nutrient better from the leaves and stems instead of roots.

Cheers
JC