I want to mix a liquid solution of KNO3 and KH2PO4 that will last me for a week rather than measuring with spoons and disolving the nutrients in water each time i dose. I want to be more accurate than a teaspoon. So what does a 1/2, 1/4, and 1/8th of a teaspoon convert to in grams? Moreover, I want to make a liter solution that will last a month for a 55 gallon and a 29 gallon.
I think I saw a website for making liquid solutions, but It was all to confusing for me.

See here:

Want more accuracy? Want daily PMDD style EI dosing?

What is it that you hope to gain by more accuracy?

Plants, tanks etc are variable, species type, biomass etc...........the dosing you do will never be one size fits all via more accurate results.

Basically you worry about accuracy in an inaccurate but variable biological world.
Things are not that rigid.
That is a good thing.

You can dose more frequently, to keep narrower ranges, then still do the water changes to prevent deviations from a standard range(which is some arbitrary range you set).

It's not some precise set point nor will it ever be.
That's why I suggest estimative...........especially at high growth rates......

the dosing calculators are plenty, we have one here, nutri calc.

Simple EI Dosing Calculator

Plug in the amounts you want etc and go from there.
If you plan on doing this, you will have to learn more about it.

Regards,
Tom Barr

This is what I found....

"This is an example of EI for a 12 week supply for a 20 gallon tank for those with teaspoon aversion.

To 1 liter of DI water add:

60 grams KNO3
18 grams of KH2PO4
25 grams of GH booster

Add 12 mls daily.
Add TMG at 2.5 mls daily.

That's it.""

Would these amounts for the "20 gallon" be the same for a 29 gallon?
If I want another solution for a 55, what would the grams be for KNO3 and KH2PO4?

Secondly, do I need to add HCl or keep this refrigerated? If I do need to add HCl, how much do I add?

Thirdly, if I want to dose every other day would I just double the dosage?

Lastly, for some reason I cannot access the calculator on this forum. It says I do not have privilege. How do I get privilege?

The only reason I want to make liquid solutions is because I don't like having to mix doses every other day and I don't have a 1/32 or 1/16th of a teaspoon. Adding a test tub sounds much easier. Note: I also have access to scales and graduated cylinders. etc.

Then just take whatever amount you want for a specific tank, multiply out for the days you want(say 2weeks = 14 days).

Add to 1 liter etc.

Say a 20 gallon tank
1/4 tsp x3 a week X 2 weeks= 3x.25x2= 1.5 tsp.

For 20 vs a 29, add 29 gallon/20 gallon = 29/20ths more mls from this same solution.

For the macros being used fast, no HCL is ever needed.
Traces yes, refrigerating can help as well.

So do not mix up that much at once, 2-3 weeks worth etc.
3rdly, yes, 2x.

See The Krib (Aquaria and Tropical Fish) for more and Chuck's cal for more on cal usage and chemicals.

Some simple Google searches will turn up your questions asap.

Regards,
Tom Barr

Chucks calc seems to be very helpful, but I have one more question.

The calc tells me how much ppm I will dose for each ml. If I want to hit a target in my tank of 1ppm of phosphate and 10 ppm of nitrate, do I want to hit that target each time I dose (I will be dosing every other day). Or do I want to add less and let it accumulate by the end of the week?

Without accurate testing, and a lot of it, there is no way to know how much accumulates by the end of the week. Remember, the plants are consuming those fertilizer elements all during the week, so you can't just add up what you dosed. As far as your target goes, only you know what you want. If you want to know you have, at one known time, 10 ppm or more NO3 in the water, then dose 10 ppm each dose. If you want to know you will never have more than 10 ppm during the week, and are doing 50% water changes each week, dose a total of no more than 5 ppm total during the week. (But, if you do that, look for your plant growth to slow down.)

This works so much better if we just follow the EI amounts, adjusting as needed based on plant growth and watching the plants carefully. I do mine in premixed solutions, by using the formula Tom showed above, adding that much of a fert to a bottles worth of doses. I use two bottles, one for micros and extra magnesium and one for the macros. I dose every day, both bottles.

Thanks for the info hoppy and Tom

This is the stock solution I ended up making:

150 gram KNO3
25 gram KH2PO4
in 1 liter.

I plan to dose 24 mls of this solution 3x a week to my 55 and ~12mls of this a week to my 29. This should last me ~2 months

With chucks cal this comes out to:

12 ppm nitrate & 1.68 ppm phosphate each dose ( 24ml every 2 days) in my 55gallon. Note: these ppm are considering 50 gallons of water in the aquarium

Anyone have any concerns with this program? Otherwise, i'll stick with this plan and watch my plants.

That's pretty rich for this tank.

I'd shoot for about 20ppm of NO3 and 3ppm of PO4 for the week.

So 7ppm of NO3 and 1 ppm per dose.

Make sure CO2 and traces are being dosed well.
If you do larger than 50%, you will have less build up, also, if you do 2x a week 50% water change, you will have less build up.

Better to do more water changes, dosing, cleaning, then tweak the CO2 carefully than sit on the hiney and watch things go sour.

Many do this for some reason, I always scratched my head when folks did that.
You can observe all day long, but the bottom line is that it's horticulture, gardening and it takes gardening and work obviously.

If you get a weed issue, you have to do a lot more work to take care of that and until things are beaten back and stabilized.

Just make sure when you do this hobby to focus on what is really important.
It's not testing.
It's not waiting to see what the algae does.
It's not some special miracle balance.

It's water changes, pruning, cleaning, adding ferts consistently, making certain the CO2 is good, not adding too much light, high plant density, herbivores, good sediments etc.

When you do disturbances, like water changes, sediment upheaval, uprooting, filter pad cleaning etc, large pruning events, etc, make sure to do a water change right away thereafter.

This will prevent many issues.

Most of the things we do are really quite basic, no big secrets.

Regards,
Tom Barr

Too rich??? You have me confused now.

If I do the math for your recommendation for a 20 gallon
which is :

60g KNO3
18g KH2PO4
in 1 liter
12mls per day

This would equal 5.8ppm per day nitrate (35 by week end) and
2.04ppm per day (14ppm by week end)


I don't understand why the plan I layed out would be so rich...the plan you lined out for a 20 gallon seems much richer???

Perhaps you forgot I planed to dose every other day?

And why can't I access certain parts of this website. I thought I was a member, but some places say I'm not privileged. Whats up with this?