Lucas Formula add back calculator here

[gdbud]

So what you are saying is that the other add back formula works this way.
You have a 9 gallon reservoir that has 8 gallons in it. You add one gallon of water then take a ppm reading then you add X amount nutrients to achieve required PPM.
Your formulas work this way.
You have a 9 gallon reservoir that has 8 gallons in it. You take your PPM reading and it will tell you the X amount of nutrients to the one gallon of water to achieve the required PPM.
This formula would be interested to me because it would elemental one step and make my reservoir PPM eraser to calculate.

 

[superusa]

So what you are saying is that the other add back formula works this way.
You have a 9 gallon reservoir that has 8 gallons in it. You add one gallon of water then take a ppm reading then you add X amount nutrients to achieve required PPM.
Your formulas work this way.
You have a 9 gallon reservoir that has 8 gallons in it. You take your PPM reading and it will tell you the X amount of nutrients to the one gallon of water to achieve the required PPM.
This formula would be interested to me because it would elemental one step and make my reservoir PPM eraser to calculate.

Indeed that is exactly what it does. before you top off the res, check the ppms. put your current ppms and target ppms into the calculator, along with res capacity, and current level (i.e. 5 gallon capacity but only 3 gallons in it right now). The calculator will say to add 2 gallons of water, and x amount of micro and bloom. mix the 2 gallons with the nutrients, ph it, and add to res. no need to check it again.

 

[gdbud]

That is exactly the the program I'm looking for!
Now can you do it for FloraNova Grow For me! Please?

 

[superusa]

That is exactly the the program I'm looking for!
Now can you do it for FloraNova Grow For me! Please?

I can but I don't have any FNG. You would have to mix 8ml of FNG in 1 gallon of 0ppm RO water, and then tell me what the ppms (@.7 conversion) is. Then i can make it up for you.

 

[gdbud]

No More guess work.

 

[gdbud]

I can but I don't have any FNG. You would have to mix 8ml of FNG in 1 gallon of 0ppm RO water, and then tell me what the ppms (@.7 conversion) is. Then i can make it up for you.

When I get home next week I will give you the PPM for 8ml of FNG in one gallon of H20.

Thanks!

 

[superusa]

When I get home next week I will give you the PPM for 8ml of FNG in one gallon of H20.

Thanks!

No problem. Make sure the water is RO as close to 0ppm as possible. And be exact when you measure the FNG. The more accurate you are, the more accurate the spreadsheet will be. I would like to get the numbers for FNB as well, and maybe the GH 3 part schedule numbers, and put them all into one excel file with calculators for each one.

 

[gdbud]

Great.
So as more people contribute their numbers for the FNB and or GH3 using RO water the better the average will be.

So let help out this program with you numbers!

 

[bendoslendo]

Could you build a function in that subtracts your starting ppm if you are using tap? I use highgrades formula currently. He supplies ppm's in this link.

Highgrade's Formula

Oh, and you're awesome

 

[superusa]

Could you build a function in that subtracts your starting ppm if you are using tap? I use highgrades formula currently. He supplies ppm's in this link.

Highgrade's Formula

Oh, and you're awesome

I already updated it. If you download again, there is an adjustment for tap water. just type in your starting ppms man. Thanks

 

[FrameOMind]

Great job, superusa.
If you have 2 systems, one that auto tops and one that doesn't, should you still use the old add-back calculation for the auto-topped res?

 

[one Q]

once Tested this should be a Sticky!!

 

[addskee]

WOW! Thank you so much for this!

 

[superusa]

Great job, superusa.
If you have 2 systems, one that auto tops and one that doesn't, should you still use the old add-back calculation for the auto-topped res?

Gets complicated here...

I adjust the controller bucket as i would any other bucket, assuming the ppms have droppped. My capacity not counting my top off res is 20 gallons, so I put 20 in for capacity and 20 in for current level. It will still tell you how much nutrients to add, even if you are not adding water. The way i determine my target ppm has to do with actual nutrient consumption, so i only have to do this once or twice to get to the proper level, then I just continuosly fill my top off bucket with the target mix.

As for your top off res... just use the calculator to get your target mix when you fill it up... hope that helps.

Another method....

 

[superusa]

once Tested this should be a Sticky!!

WOW! Thank you so much for this!

No problem. Test it out. Let me know any feedback.

 

[javtfs]

Hello,

How would you make calculations if my ec meter reads ec 1,1 and I have a 60 liters reservoir ?

target ec 1,2 and liters left 40 ??

 

[one Q]

Listen. Can you go ahead and make this an Iphone App. Just make the Icon an "L" and not weed oriented. So that i can not open the Lappy for this calculations.

Thanks ahead of time.

 

[superusa]

Hello,

How would you make calculations if my ec meter reads ec 1,1 and I have a 60 liters reservoir ?

target ec 1,2 and liters left 40 ??

1.1EC = 770 PPM
1.2EC = 840 PPM
40 Liters = 10.6 gallons
60 liters = 15.9


This calculator uses .7 conversion, Multiply your EC by 700 to get ppm

 

[superusa]

Listen. Can you go ahead and make this an Iphone App. Just make the Icon an "L" and not weed oriented. So that i can not open the Lappy for this calculations.

Thanks ahead of time.

I am not sure if you are serious or not, but I have no experience with iphone programming. I could probably do it in C++ but I would have to look into the iphone thing. I am in college right now so I will see how much free time I have. I would be more inclined to write it for android since my phone is android and I could test it.....i do have an ipod touch, so i will think about it. If anybody else has iphone programming experience i that would be great.

 

[FrameOMind]

superusa, to program native apps for the iPhone and iPod touch, you need to have a dual-core Intel Mac to develop and compile on. They use a different flavor of C that is completely object-oriented.

Your best bet would be a web app using javascript that could run on just about any web browser (including mobiles) regardless of OS. Actually, I have been using a web based Lucas top-off app (written in php) for years. I recently ported it to javascript. It does both 2-part Flora and 1-part Nova, and both 0.5 and 0.7 TDS conversion factors. It doesn't account for starting water TDS though (yet). I always used RO/DI.

I tested it against your spread sheet, and the results are the same when compared. I approached the calculations basically the same way that you did. I used TDS values for the nutes that were once posted on the old CW. Since seeing your spreadsheet, I copied you and added the ability to drop the target TDS and also added the add-back water into the calculations.

When I used this app before, I used DWC systems that auto-topped. Now I'm using E&F with manual top-offs and was just doing 1/2 strength on all top offs and dumping halfway through. That is going to change now that I changed the app.

Thanks for the inspiration.

BTW:
1 mL of FloraNova bloom in one gallon of RO is ~161 ppm @ 0.7