Dosing EI dry ferts for the 1st time


Junior Poster
Mar 7, 2009
Just want to make sure Ive got this all right.

I have a 75 gallon moderately planted (planted well but not very dense). 2x54W T5HO's and 1 regular fluorescent, pressurized CO2.

50% H20 change-weekly
3/4 Tsp-KN03 3x a week
3/16 Tsp-KH2P04 3x a week
1 Tsp-GH booster once a week
15ml 3/16Tsp-Trace 3x a week
4-8ml-Fe/Iron 3x a week

Here are my questions...

I have a PH of 8.6 according to me water report, but it measures 7.2 in the tank, so do I need a GH booster? but im not sure as I cant find the GH on the report.

If I dont need a GH booster would I need to dose K2SO4? The old charts suggest to does K2SO4 but now Im seeing the GH booster in its place.

Also Im reading that with high light you would need the K2SO4... since I have high light would I need to dose K2SO4?

Now I have a 75 gallon but there is 3 inches of substrate in there and a lot of rocks and plants, with that I may have more like 60 gallons of water... my tank is only moderately planted so Im wondering if I should follow the 40-60 gallon or the 60-80 gallon recommended EI dosing chart?

Here is my plan, please let me know if this is accurate (I can adjust if it is established that I need the K2SO4)...

Sunday-----Day 1) 50% H20 change, 3/4tsp-KN03, 3/16 tsp-KH2P04,
Monday-----Day2) 3/16 tsp CSM+B,
Tuesday----Day3) 3/4 tsp-KN03, 3/16 tsp-KH2P04,
Wednesday-Day4) See day2
Thursday---Day5) See day3
Friday------Day6) See day2
Saturday---Day7) Nothing



Lifetime Charter Member
Lifetime Member
Mar 12, 2009
Dry dose by volume isn't something I've done, so I don't know the densities. As for the rest...

Add the potassium, it doesn't hurt. Potassium is one of the most frequently seen deficiencies. It's hard to dose too much while following most guidelines.

Dose by water column size, not tank capacity.

I follow a similar dosing schedule to yours, though micros happen 3 days a week with mine. It's worked for me so far.



Guru Class Expert
Mar 5, 2009
You can start the 60-80 (as it won't hurt) and than backup progressively to the 40-60 stage observing the plants. It's better than start low and hurt plants if not enough

I also simplified the EI dosing and it works fine

day 1: WC 2h after lights on + NK + micro + P 30mn later
day 2: rest
day 3: (NK + micro) in evening after lights off + P next morning before lights on
day 4: rest
day 5: (NK + micro) in evening after lights off + P next morning before lights on
day 6: rest
day 7: rest