your welcome Farmer John!
Make sure you take your measurements when the res is full (topped with water), otherwise you'll just measure the tendency (more nutes or more water were used, but no idea how much).
You certainly have heard of people telling you that each plant is different and needs different nutes.. oh well, i think we all have/had very similar plants, hybrids with lot of vigor, growing fast in good conditions. By using a nute level that is not too high and not too low, we can still adjust to each plant by altering the frequency of adding/replacing the nutes. Meaning when plants eat a lots, we replace/add the nutes more often
I do not recommend not changing the res without a EC/TDS meter, but some folks have a good feeling when its time to replace. GH recommends changing the res at 100% addback, that means, once you added the same amount of water that your res/bucket/tub size is, its time for new nutes. But with a small res this is not nessecarly true... sorry, can't help you much on that one.
One problem you might run into is the low res size (don't know your light yet, just assuming its big). If the plants do use more water than nutes, your nute concentration will rise(and the pH fall), its easy to reach toxic levels like that and cause nute burns.
One way to prevent this is a big res size, another is using an automatic floatvalve for automated top offs.
Lucas recommends at least 1.6 gals, better yet 2gals per 50W of lights, that would make 16gallons(ca.60 Liters) for 400W HPS, 24gals for 600W HPS (ca. 90 Liters) and 40gals (ca. 150 Liters) for 1000W HPS.
These numbers might seem high at first, but you'll appreciate the stability, and so will your plants.
I was growing in individual 5 gal buckets, had to adjust the pH/EC once daily in late veg, and twice daily in late flower... for each bucket... worked my ass off, but still couldn't keep it stable
A 16gal tub for my 430W HPS did the trick for me
Bigger res means:
- more stable pH
- more stable EC
- more stable DO (dissolved oxygen)
- more stable nute temps
Its worth it IMO.
geez, time for me to stfu
mace
You add/change the mix when the ppm's fall (and the pH rises, weaker nutes have a higher pH than stronger nutes, you can control the pH a bit via nute strength in RO water).
Make sure you take your measurements when the res is full (topped with water), otherwise you'll just measure the tendency (more nutes or more water were used, but no idea how much).
You certainly have heard of people telling you that each plant is different and needs different nutes.. oh well, i think we all have/had very similar plants, hybrids with lot of vigor, growing fast in good conditions. By using a nute level that is not too high and not too low, we can still adjust to each plant by altering the frequency of adding/replacing the nutes. Meaning when plants eat a lots, we replace/add the nutes more often
I do not recommend not changing the res without a EC/TDS meter, but some folks have a good feeling when its time to replace. GH recommends changing the res at 100% addback, that means, once you added the same amount of water that your res/bucket/tub size is, its time for new nutes. But with a small res this is not nessecarly true... sorry, can't help you much on that one.
Yes, thats correct!
An EC of 1.9-2.0 isn't high for a plant in good conditions with a lots of light (>50W per square foot), the original GH flower formula 1/2/3 uses teaspoons as measurement(ca. 5ml) and translates into 5-10-15 ml per US gallon, thats an EC of 2.5mS/cm, even stronger than 0-8-16. Anyways, for stressed plants most nutes are to strong, the solution is to remove the stressing factors.
One problem you might run into is the low res size (don't know your light yet, just assuming its big). If the plants do use more water than nutes, your nute concentration will rise(and the pH fall), its easy to reach toxic levels like that and cause nute burns.
One way to prevent this is a big res size, another is using an automatic floatvalve for automated top offs.
Lucas recommends at least 1.6 gals, better yet 2gals per 50W of lights, that would make 16gallons(ca.60 Liters) for 400W HPS, 24gals for 600W HPS (ca. 90 Liters) and 40gals (ca. 150 Liters) for 1000W HPS.
These numbers might seem high at first, but you'll appreciate the stability, and so will your plants.
I was growing in individual 5 gal buckets, had to adjust the pH/EC once daily in late veg, and twice daily in late flower... for each bucket... worked my ass off, but still couldn't keep it stable
A 16gal tub for my 430W HPS did the trick for me
Bigger res means:
- more stable pH
- more stable EC
- more stable DO (dissolved oxygen)
- more stable nute temps
Its worth it IMO.
geez, time for me to stfu
mace
