Why dose dry ferts?

[Jeff120]

Found this on another forum, thought I'd share

Cost of dosing dry vs Seachems line

1 pound of dry fert = x liters of Seachem's ferts
1 lb of KNO3 = 3.7 L of Nitrogen
1 lb of K2SO4 = 4.5 L of Potassium
1 lb of KH2PO4 = 67.0 L of 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 Nitrogen
1 lb of K2SO4 costs $2 = $58.50 of Potassium
1 lb of KH2PO4 costs $3 = $871.00 of Phosphorus

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

[John G]

But for a normal size aquarium, say 75 gal, how much do you save over a year? Is it worth it?

[krisw]

Yes, it's worth it... For a 75G with CO2 blasting, and high light you'll likely go through at least one 2L of each Seachem product (more for some than other due to differing concentrations). Of dry products, 1 pound of each should last at least 1-2 years.

[John G]

So 1 lb of each would cost $7, and last two years. I just checked Foster& Smith and they had 2 liters of Seachem Flourish for $19.49; 2 liters of Seachem phosphorus for $20.79, and 500cc of trace for $3.69. Two bottles of each would be about $88, for a savings of $81 over two years, or about 85 cents a week, or a little over a dime a day.

If you're worried about money, I don't think it is worth the trouble for a dime a day. If you like to experiement and so on, then it may be worth it.

[Jeff120]

Price per pound of dry varies, 2-3 from one source. Seems as if you dont dose very much John. I guess for someone like you it dosent pay off to get the dry. If a 2 liter of each last you a year. Dry would last you 4-5 years.

This dosent include trace, CSM+B-I think it sells for around 12.00, is significantly cheaper then Seachems flourish. I bought a pound of it 2 years ago and am only about half way through it. 1 T. in 250 ml of water is pretty close to flourish.

I didnt write this up or figure the numbers, just though it was interesting to see what the saving could be if you are dosing regularly with the Seachem line

[jcali10]

I prefer to buy dry ferts; seems more economical. Your not paying for water to be shipped. I'm dosing PPS Pro daily. Tried the Standard Solution for a week, now I am going to try the Nitrate Free Solution, and see how that works out. Just mixed up 300ml today.

[krisw]

And just a note, that this is not at all saying that Seachem products aren't effective. In fact, I use both Seachem products, and dry ferts, depending on the tank. There are differences too, for example, Seachem Nitrogen contains both KNO3 (the standard dry fert dosed) and ammonium, which may be a more preferred nitrogen source for some plants. Additionally, Flourish is often purported to be superior to CSM+B, probably due to the basis that it contains more micronutrients than CSM does, such as Mg if I remember offhand. So, it's not a total Apples to Apples comparison, but particularly on larger, hightech tanks, that the cost difference could be substantial.

This actually corresponds well to a set of tests I've been doing lately with the Seachem Macronutrients when working on eliminating algae from my tank. I've been testing N and P every day for the last two weeks. In that time, to maintain N levels between 5-10ppm and P levels of .5-1ppm I've have to dose over 150mL of Seachem Nitrogen, and over 100mL of Seachem Phosphorous. That means that just on my 40G tank, I'd burn through 4 2L's of Seachem Nitrogen, and 2 2L's of Phosphorous per year, at an expense of roughly $120 just for those two nutrients. I'll likely be switching to dry ferts for this tank once I finish the 2L's I have.

[jcali10]

Kris makes a good point on fert usage with his 40G example, if you have a large aquarium/s, dry ferts are probably the most economical solution.

If I was dosing a small tank of 10G or less, I think dosing drops would be more desirable. Dry ferts would still work if your solution uses 1ml per 10 gallons as mine does. If 20 drops equals one ml, then you can use 10 drops for a 5G, and 5 drops for a 2.5G.

I add MgSO4 to my solutions and dose Fe seperately in the form of CSM+B.

[ingg]

Now think of doing it on a 100+ gallon hi tech tank.

In combination, many of us are dosing 100+ gallons - maybe not in individual tanks, but collectively?

[Ben Belton]

I like dry better just because it is less troublesome. I can scoop out a tsp of KNO3 and throw it into the tank in a second.

I do make my PO4 into a solution though.