I always think about fertilisers in terms of "ions", plants can only take up fertilisers as ions and every NO3- ion etc. is the same as every other NO3- ion, it doesn't matter where they come from.When purchasing my fertilizer I mistakenly bought a PPS PRO fert package instead of an EI one. What are your thoughts/experience with the two methods?
By the look of it.The kit I bought is here.
So if I'm understanding correctly. The PPS PRO is just a lower dosage the the EI?
You can potentially get precipitation of phosphate (from the macro) and iron (from the micro mix) compounds. Because you have a relatively dilute feed with PPS, it is less of an issue.PS PRO method it states to dose both macro and micro (separate solutions) at the same time but I've read in other posts and on the EI method to dose them on different days.
Just look at <"the plants">, if they are a nice green and growing you are dosing enough. A <"floating plant"> is the best "canary", because it takes CO2, and PAR, out of the equation.Also I have not picked up a TDS meter yet. In the meantime is there any other way to know I'm dosing enough?
If the plants are looking OK? Just keep on going.I'm attaching a pic of my current dosage. I'm using the highest volume one, the high light dose. However I haven't dropped down to 1 WC a week yet. I'm currently performing a WC every 2 days.
Once you have the TDS meter, measure the TDS every day for a week or so. That will give a datum range. At that point I'd go to one water change a week, and then see how much the TDS rises over the next couple of weeks.
If it remains near the datum range one water change is fine, if it continues creeping up you can either go back to two water changes or lower the dosing to the "medium light" option.
There isn't really a value, it is going to depend upon the starting point. Have a look at Jordi's (@parotet's) comments in <"Setting up....">.What levels am I needing to achieve?
It would really just be if the value continually rose, eventually it will stabilise whatever happens.How much of an increase over the week would you consider too great?
Here are my TDS readings from the first week of using the meter.
Tap - 360
After 50% WC
Mon - 370
Tue - 383
Wed - 398
Thur - 409
Fri - 420
Sat - 427
50 % WC
Sun - 417
Yes, probably should have done.
That is what I'd expect as well, conductivity is a linear value (at the values that interest us) so the ppm TDS reading should be somewhere near (360 + 417)/2.I’d’ve expected it to drop to ~ 390 - 400 after 50% water change
The 0.55 ke value is where the major salt in the water is sodium based (so usually NaCl). All the meters I've seen in the UK use ke 0.64 as a default, which is the conversion factor when Ca++ and HCO3- (from CaCO3) are the most frequent ions present.where TDS is expressed in mg/L and EC is the electrical conductivity in microsiemens per centimeter at 25 °C. The correlation factor ke varies between 0.55 and 0.8.
Sounds likely........some plants around prior to the WC, I'm thinking the TDS count was a bit higher after that.
I'd probably give it another week, and then if the TDS values are still rising up the water change frequency (or volume).could always change more water 50% is simply a guide line I like to do 70% weekly that brings my TDH back down to just above my tap level
so could be you TDS meter/pen and was the water at the same temp each time