fertilizing a 77 gallon tank. Please help.

[sasa]

Hi,

The EI (Estimative Index of Dosing) method says that for a 20 gallons with 5.5 watts/gal the dosing will be:
1/4 teaspoon of KNO3 4x a week (every other day)
1/16” teaspoon of KH2PO4 4x a week (every other day)
Traces added on off days as the macro nutrients, so 3x a week, 5mls each time.

Using the Chuck's calculator that will be:
KNO3 = 11.29ppm Nitrate - 7.13ppm Potassium
KH2PO4 = 2.66ppm Phosphate

Now, If I translate that to my 77 gal tank with 2.02 watts/gal and fluorite+eco-complete+gravel substrate, the dosing will be:
1 teaspoon of KNO3 (11.8ppm Nitrate - 7.45ppm Potassium)
1/4 teaspoon of KH2PO4 (2.88ppm Phosphate)
Traces 15mls of Flourish Trace™.

Am I doing the calculations right or am I forgetting something? If my level of light is much lower than Barr's setup should I dose macros just 2 times per week and traces once a week?

My tank is going to be medium to heavy planted with no fish at the beginning just shrimps (at least until I get used to the plants or they get used to me )

Thanks for any help

 

[malkore]

seems like a lot of phosphate to dose. I don't let mine go much over 1ppm, and I have more light than you.

Are you injecting CO2?

 

[sasa]

hi malkore,

I haven't set up my tank yet but I have everything ready. This is the stuff I have:
* 77 all glass tank
* 160 w/gal fluorescent light (power-glo)
* eco-complete + fluorite + gravel substrate
* pressurized C02 with jbj regulator and powered reactor

I only have the following plants available in my LFS (for medium light setup):
* Cuban Broadleaf Chain
* Echinodorus Angustifolios
* Tenellus
* Ozelot Sword
* Anubias nana and barteri
* bolbitis heudelotti
* cryptocorine wendtii (green and tropica)
* cryptocorine willissi (lucens)
* Cyperus helferi
* Madagascar lace
* Hornwort
* Java moss
* Java fern

Most of them are slow grow (I couldn't find anything else)

I'm planning to have shrimps at the beginning to help me with algae.

This is the fertilization schedule I was planning to use:

Saturday:
50% water change
0.5 teaspoon KNO3, 1/24 teaspoon KH2PO4

Sunday, Tuesday and Thursdays:
5 mls of trace

Monday, Wednesday:
0.5 teaspoon KNO3, 1/24 teaspoon KH2PO4

Do you think is too much?? How much should I use? I was hoping to setup the tank this weekend but I want to have the dosing right from the beginning.

Thanks for your help and time,

sasa

 

[malkore]

First of all, NEVER dose nitrate and phosphate until you test those levels, and know for a fact you need to dose.
With 2wpg, dosing phosphate 3x a week is bound to get you in trouble.

And as far as 'from the beginning'...you shouldn't have to dose a brand new tank for at least 3 weeks...many advise waiting 6 weeks before dosing any ferts. Just stick to weekly water changes to keep trace levels decent.

 

[gone fishin]

first, buy another light.


1 TBL Plantex
1 TBL MgSO4
2 TBL Potas Sulf
1.5 tsp Potas nitrate

Start with 2ML/day
Reduce to 1 per day

500 ML Distilled Water

Thats my recipie

 

[gone fishin]

BTW mine is a 90 gal

 

[malkore]

There's nothing wrong with the light. It's a 4x40 NO fluorescent fixture, giving them a smidge over 2wpg. A fine medium tank setup, since pressurized CO2 is in use.

 

[travis simonson]

You're going to get all sorts of differing advice on dosing nutrients. What you end up doing in the long run should be based upon your observations of how your tank reacts to a set dosing regimen (the Estimative Index approach is the place I would recommend as a start because it's hard to go wrong using it). You're in luck because you're using CO2 on 2wpg tank, which is very hard to go wrong with as long as you stick to your maintenance schedule. Like you said, you've got a lot of slow growing plants so don't expect your nutrient uptake to be very high, at least at the beginning. Swords and Crypts can suck up a huge amount of nutrients once they get comfortable, but at the beginning they will be hesitant.

My advice is to monitor NO3 levels daily after you first set the tank up. This will give you a good idea of when the nitrate spike occurs and will let you know when NO3 levels finally begin to drop toward zero. Once NO3 begins to approach 0-5 ppm I would recommend beginning your dosing regimen. I've gotten my dosing down to a pretty close margin and thought it might help if you took a look at it. All doses are listed in ppm's so just use Chuck's calculator to determine the amount necessary for equivalent ppm's in your 77G tank. And remember to subtract about 10-15% of the water volume to account for displacement due to substrate, decor, etc. when using Chuck's calc. In your case I would probably recommend stating your tank volume as 70 gallons. Also, make sure to check the radio button for dry ingredients if you are adding them directly to the tank rather than in solution. Hope this helps

Travis' Dosing Routine:

SAT: 50-70% Water Change
KNO3 (Potassium Nitrate) + 10-15 ppm
KH2PO4 (Mono-Potassium Phosphate) + .5-1.0 ppm
K2SO4 (Potassium Sulfate) + 10 ppm

SUN: Trace Mix* @ 5ml/20G of tank volume

MON: KNO3 (Potassium Nitrate) + 10-15 ppm
KH2PO4 (Mono-Potassium Phosphate) + .5-1.0 ppm
If no KNO3 dosing then K2SO4 (Potassium Sulfate) + 5 ppm

TUES: Trace Mix* @ 5ml/20G of tank volume

WED: KNO3 (Potassium Nitrate) + 10-15 ppm
KH2PO4 (Mono-Potassium Phosphate) + .5-1.0 ppm
If no KNO3 dosing then K2SO4 (Potassium Sulfate) + 5 ppm

THURS: Trace Mix* @ 5ml/20G of tank volume

FRI: Day of rest (i.e. no dosing)

SAT: Rinse. Repeat.


*Trace Mix

500 mL Water (Dose on Sun - Tues - Thurs)
1 TBL MgSO4 (Magnesium Sulfate) = Mg + 0.03 ppm/mL or Mg + 0.6 ppm/20 mL Dose
1 TBL Plantex CSM + B (Iron and Traces) = Fe + 0.0025 ppm/mL or Fe + 0.05 ppm/20 mL Dose
1 TSP Iron Chelate (Fe only - Get it from Greg)
1 TSP CaCO2 (Calcium Carbonate - again Get it from Greg)

Note: This recipe is what works for me, but your tank may be different. Just observe how your plants respond and, if you do feel you need to adjust, try to do it gradually.

Ideal nutrient levels:

NO3: 10-15 ppm
PO4: .5-1.5 ppm
K: 10-20 ppm (Although at the time of this writing no reliable K test kit exists)
Fe: .1-.2 ppm (Don't even try to measure this, it simply doesn't work, green leaves on H. difformis are the best indicator of adequate trace levels)


And if you have problems figuring out what ppm's to use for your tank get Chuck's Calculator here:

http://www.csd.net/~cgadd/download/aquacalc_setup.exe


All dry fertilizers mentioned above may be purchased at www.gregwatson.com


For best results use LaMotte/Hach test kits only. Measurements gained without these kits may vary widely.