Hey Tom... NPK solution...

Re: Hey Tom... NPK solution...

Assuming you want to mix up 500 ml of NPK solution, and that you want it to last 20 doses, for example. You want 20 times the dose of each fertilizer mixed in with the 500 ml of water. Then you dose 1/20th of the 500 ml each time you dose. You do have to be sure that you can dissolve that much in that little water. Unless you are using an auto-doser, which doses liquids only, it is a lot easier to just dip a tiny measuring spoon into the fert and dump it in the tank.

 

Re: Hey Tom... NPK solution...

Most of us just dump the ferts in the tank. We are only talking about a tsp or less of any one of them, for most sizes of tanks. And they all dissolve pretty quickly. CSM+B, a trace mix, dissolves slower, but can still be dosed that way.

 

Re: Hey Tom... NPK solution...

I mix it in water immediately prior to dosing. However, the main reason I do this is because I have 2 tanks, and one is 29g -- so the amounts are small and hard to measure. So I mix the amounts for both (65 and 29g) at once, and I have carefully marked my bottle in 1/3rd's, so I take 1/3 for th3 29g and 2/3 for the 65g. However, I find it easy to disolve the ferts, so even if I was dosing one tank I would probably mix it in tank water first -- it seems pretty simple.

 

Re: Hey Tom... NPK solution...

May as well dry dose into the sump. If you don't have any criters in there it won't make a difference, and is the perfect place to dissolve ferts. Even if you do have criters in the sump, you probably will not have a problem (I do not).

FWIW, when I dose from solution I just target a nice easy dose (say, 5mL/1tsp) to reach my targets. Your plan of dividing the trace mix volume works of course, its just a pain in the ass to measure that several times a week. Also, its okay to round up under EI unless you want to be more exact about ppm. Use Chuck's calc or the Fertilator or such if that is important: http://www.csd.net/~cgadd/aqua/art_plant_dosage_calc.htm

You can go up and down on CSM+B depending on your target Fe ppm. Here is my calculator if you want to calculate to ppm or play with that recommended dosing: http://justanothertank.com/calcs.php . (Greg's 1tsp in 500mL, 5mL doses/20gals is ~.12 Fe ppm. I like .3ppm Fe. If I remember correctly, Tom Barr and Greg have both dosed to 1.0ppm Fe with no reported issues. Experiment.)

Do not forget to include the sump's water to the total volume when calculating your ppm.

Good luck,
Joe

 

Re: Hey Tom... NPK solution...

I agree (from experience) with the above. I have a 65g (figure 55g actual) tank. I have 5 2L bottles on it, with two reactors. I figure, from results, that my CO2 is barely adequate. I have slight algae compared to my 29g tank which has 3 2L bottles and one reactor and has no algae. Actually I figure both are marginal, the 29g being less marginal

My plan is to move to pressurized CO2 on the 65g and move a bottle to the 29g.

Changing 8 2L bottles is a pain, even though mine seem to last for 14 days.