mixing dry k2so4...confused - The Planted Tank Forum
LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 03-12-2010, 02:35 AM Thread Starter
Algae Grower
PTrader: (0/0%)
Join Date: Nov 2009
Location: Delray Beach, FL
Posts: 26
Question mixing dry k2so4...confused

i just started mixing my own ferts and used the calc that everyone directed me to here. KH2PO4 and KNO3 were no problem. according to the Calc i would need 430 grams of K2SO4 in 125 ml to get 20 ppm per ml. 430 grams wont fit in 125 ml bottle so i did some more research and found many people dry dose with K2SO4 with no problems. But i am confused how to measure the dry dosing and how to test and keep a constant (or as close to) 20 ppm. am i to assume i am at 0 ppm currently?

my tank:
20 gallons
65 watts on 11 hours
flourite (25% gravel) substrate
dose flourish comprehensive 2x week
dose flourish excel daily (NO CO2)

Ngiltner is offline  
Sponsored Links
post #2 of 3 (permalink) Old 03-12-2010, 03:28 AM
Planted Member
PTrader: (1/100%)
Join Date: Dec 2009
Location: Wyoming
Posts: 221
You have some numbers off somewhere. Seeing as how 1mg per liter is 1ppm. 1ml water = 1g, so 125grams would be 100% in 125ml.

430mg in 125ml would be 3440ppm solution. If I'm remembering everything correctly then adding 430mg to 75L of water (ie your tank) should be about 5.7ppm. Which seems about right for EI because you will be adding that 3 times a week as well as adding the other fertz that will also add some of the same elements.

However its been too long since I've had to figure out solutions and mixing to remember all the math.
Erloas is offline  
post #3 of 3 (permalink) Old 03-12-2010, 04:51 AM
Wannabe Guru
nokturnalkid's Avatar
PTrader: (83/100%)
Join Date: Apr 2007
Location: HI, but Pueblo, CO for now
Posts: 1,239
The thing about k2so4 is that it isn't very soluble. You can make a make a solution but it may be a bit dilute. k2so4 is easiest dosed dry. Remember also, you are getting potassium from kno3 and kh2po4. So, you need to factor those sources for hittin a target ppm. The thing about ferts, you don't have to be exact. Close is good enough. As far as I know, there isn't anything bad with overdosing k unless you get to the 100ppm or so range. But, that will be very hard to do unless you want to.
nokturnalkid is offline  


Quick Reply

Register Now

In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome