Comparing fertilizer prices

[firestorm]

Well I stopped by quick grow hydroponic store today, bought myself 200g of chelate (trace), a 500g container of KN03, and more than 500g (but he only charged me for 500) of K2SO4. I paid only $34 for all of these, and they will most likely last me at least 6 months using them on my 35 gallon and my 90 gallon tanks. Compare that to the $25 or more for a 500 mL bottle liquid you get from the LFS, which only lasts maybe a month or a little more. But add the bottle of trace onto that as well, and it will cost you more. In the long run I expect to save at least $40-50 each year by buying them dry. My conatiner of KHIt is definitely worth buying dry and in bulk if you are dosing several tanks, or larger ones. Just wanted to share this bit of advice with you guys

[jvision]

I switched over to dry ferts for macros a long time ago, but still liked Tropica Master Grow for micros. However, I'd go thru a large bottle of TMG in a little less than a month on my 135. I could no longer justify the cost of not going dry for macros as well.

[Kayen]

Here's a nice resource:

"Hi

Check this out. You might be surprised.

1 pound of dry fert = x liters of Seachem's ferts

1 lb of KNO3 = 3.7 L of F. Nitrogen

1 lb of K2SO4 = 4.5 L of F. Potassium

1 lb of KH2PO4 = 67.0 L of F. Phosphorus

Rex's price of 1 pound of dry ferts compared to DrsFosterSmith.com regular price of $26 for 2 liter jugs of Seachem's ferts

1 lb of KNO3 costs $2 = $48.10 of F. Nitrogen

1 lb of K2SO4 costs $2 = $58.50 of F. Potassium

1 lb of KH2PO4 costs $3 = $871.00 of F. Phosphorus

The price of 3 lbs of Rex's ferts is $7 and the 75.2 liters of Seachem's ferts price is $977.60.

You can buy 140 lbs of Rex's dry ferts for the price of these Seachem's ferts.

I never realized that Seachem's ferts are this expensive. I've read about people claiming that F. Potassium is a weak solution, but I never realized that F. Phosphorus is so weak. I went to Seachem's site to double check on the calculators. I came up with the same amounts that are shown in Seachem's dosing directions for each of these products.

I used Chuck's fert calculator and the fertfriend calculator to arrive at the equivalent ppm amounts of Seachem's ferts needed to equal the ppm that 454 grams of the dry ferts yield.

I used Chuck's calculator to find the ppm of 454 grams of the three dry ferts in 100 liters of water. Then I used the fertfriend calculator to find out how many liters of Seachem's ferts that it takes to equal this same ppm.

- 454 grams of KNO3 in 100 L yields 2785 ppm of NO3 that is equivalent to 3.7 L of F. Nitrogen.

- 454 grams of K2SO4 in 100 L yields 2040 ppm of K that is equivalent to 4.5 L of F. Potassium.

- 454 grams of KH2PO4 in 100 L yields 3170 ppm of PO4 which is equivalent to 67.0 L of F. Phosphorus.

Here's a little bit more about the calculations. This is Seachem's dosing directions results from their web site compared with the fertfriend results to determine it's accuracy. You can see that it is pretty accurate.

- F. Nitrogen: "DIRECTIONS: BEGINNER: Use 2.5 mL (half a cap) for each 160 L (40 gallons)...EXPERT: The beginner dose raises nitrogen by the same degree that 1 mg/L nitrate would." The fertfriend calculates 1.2 mg/L for 2.5 mL in 160 L.

- F. Potassium: "DIRECTIONS: Use 1 capful (5 mL) for every 125 L (30 gallons). This dose raises potassium by 2 mg/L." The fertfriend calculates 1.8 mg/L for 5 mL in 125 L.

- F. Phosphorus: "DIRECTIONS: BEGINNER: Use 2.5 mL (half a cap) for each 80 L (20 gallons)...EXPERT: The beginner dose raises phosphorus by 0.05 mg/L (0.15 mg/L phosphate)." The fertfriend calculates 0.15 mg/L for 2.5 mL in 80 L.

You can see the fertfriend is fairly accurate. You have this...

- F. Nitrogen: 1 mg/L vs. 1.2 mg/L - NO3

- F. Potassium: 2 mg/L vs. 1.8 mg/L - K

- F. Phosphorus: 0.15 mg/L vs. 0.15 mg/L - PO4

(I rounded my calculations to one decimal place for simplicity.)

Left C"

Original thread: http://www.rexgrigg.com/phpBB2/viewtopic.php?f=5&t=107

Also in asking him for his permission to post this he also provided these links :

If you need these:

Chuck's calculator: http://www.csd.net/~cgadd/aqua/art_p...osage_calc.htm

FertFriend: http://www.fishfriend.com/fertfriend.html

This Excel based calculator may be helpful to some people.

http://www.aquaticplantcentral.com/f...tor-chart.html

[firestorm]

Very great info Kevin. I think it proves that buying dry in bulk is much cheaper in the long run than buying in liquid form from your LFS. If I only had a single smaller planted tank, then maybe I would have stuck with liquid, but since I don't I will definitely be buying from the hydro store from now on

[algae farmer]

Very great info Kevin. I think it proves that buying dry in bulk is much cheaper in the long run than buying in liquid form from your LFS. If I only had a single smaller planted tank, then maybe I would have stuck with liquid, but since I don't I will definitely be buying from the hydro store from now on

I buy my ferts in 50 lb. bags. Seems to last a life time, but then again I'm running 300 + gal. of planted tanks and I go through a lot. Especially KNO3. You could do a group purchase and then split the order. Check Appache Seeds for pricing and availability.

take care.

PS

[firestorm]

Very great info Kevin. I think it proves that buying dry in bulk is much cheaper in the long run than buying in liquid form from your LFS. If I only had a single smaller planted tank, then maybe I would have stuck with liquid, but since I don't I will definitely be buying from the hydro store from now on

I buy my ferts in 50 lb. bags. Seems to last a life time, but then again I'm running 300 + gal. of planted tanks and I go through a lot. Especially KNO3. You could do a group purchase and then split the order. Check Appache Seeds for pricing and availability.

take care.

PS

Thanks, maybe we could try that. I won't be anytime really soon, I now have all the ferts I need for a few months.

[Ishkabod]

I've read the info on the different ferts mentioned but there was nothing on Organic carbon Or Iron supplements. These are the only two fertilizers i ever use. Both from seachem. Does anyone know of an alternative cheaper substitute.

Thanks

L

[Kayen]

Iron tends to be in liquid form also attainable from hydroponics stores from what i hear, and nothing on carbon supplements aside from the popular excel.

[jvision]

Depending on the size of aquarium, Excel may become too expensive. I found that after 25gal or so, dosing as per instructed becomes a bit pricey - then, I'd switch to CO2 gas (which is organic, BTW)

[firestorm]

I still only buy liquid seachem iron, 1 capful treats 50 gallons, so I find it is not a huge expense. I only use excel on my small planted tanks (5-10gal) otherwise I use CO2 systems whether they are pressurized or DIY systems.