Thank you! And do I add it everytime I add more nutes? I'm running sterile (h202) and plan on only changing out the water when I flip them to flower, unless some issue arises that requires a water change. My plan is to start at 1/4 strength calmag and increase to 1/3. And increase more if plants start to look deficient.Go ahead and use some but I wouldn't go over 1/2 the max amount on the label. I mostly used AN for 20 years and always used RO or distilled water. Our tap water comes from a dugout on my property and is about 400ppm and pH 8+.
Decent sized dugout as you can see from the pic I took recently with my new drone.
View attachment 5319296
When to begin nutes in rdwc
- Thread starter 420Mn
- Start date
Look at your nutrient's ingredients. If they have Ca and Mg don't add more. If they do not contain Ca and Mg and you are using water without Ca and Mg add it. If they contain one and not the other add the missing one in small amounts.
Hope that helps
OldMedUser
Well-Known Member
That sounds perfect. During veg just add more nutes in the same ratio to keep the ppm/EC in the target range or raise it as the plants get bigger. I start at 300ppm, (Hanna scale or .5), then go to 500 as they start growing faster then up to maybe 750 for most of the rest of veg unless they look like they need more. We have very low RH so I need less ppm to prevent toxic salts buildup in the plants that will show up mid-flower with leaves burning and going all crispy hard and thick feeling. Low nutes the leaves go yellow and limp.
I'll add a half dose of Big Bud a week before flipping to flower and have the ppm 25% higher as the stretch is a massive growth spurt so they need lots of all nutes to do their best during that period. Then I allow the ppm to drop to where it was before the flip and reduce the amount of N and P they get by feeding Lucas Formula style or a ratio of 0-1-2 of No Grow and 1ml Micro to 2ml Bloom with a little Big Bud for all the goodies that are in that. I get the powder Big Bud as it lasts a lot longer on the shelf than the liquid one. A dash of calmag here and there and Epsom Salts is about all I ever used other than the nutes and BB.
Have fun!
for reference, this is the feeding schedule. If you look above the mixing chart it has instructions for when using reverse osmosis water and how much calmag to add. The feeding chart for calmag decreases as the other nutrients are increased. That makes me believe my nutrients have cal and mag but in small concentrations that are too low for ro water. As the nutrients are increased the smaller concentration of cal and mag, which would be plenty when using tap water, increase, causing the need to use less calmag. Not sure if this chart and ro water info alter your advice in any way?
Attachments
Thank you man! I took a screen shot of your message to reference. You've been a huge help!That sounds perfect. During veg just add more nutes in the same ratio to keep the ppm/EC in the target range or raise it as the plants get bigger. I start at 300ppm, (Hanna scale or .5), then go to 500 as they start growing faster then up to maybe 750 for most of the rest of veg unless they look like they need more. We have very low RH so I need less ppm to prevent toxic salts buildup in the plants that will show up mid-flower with leaves burning and going all crispy hard and thick feeling. Low nutes the leaves go yellow and limp.
I'll add a half dose of Big Bud a week before flipping to flower and have the ppm 25% higher as the stretch is a massive growth spurt so they need lots of all nutes to do their best during that period. Then I allow the ppm to drop to where it was before the flip and reduce the amount of N and P they get by feeding Lucas Formula style or a ratio of 0-1-2 of No Grow and 1ml Micro to 2ml Bloom with a little Big Bud for all the goodies that are in that. I get the powder Big Bud as it lasts a lot longer on the shelf than the liquid one. A dash of calmag here and there and Epsom Salts is about all I ever used other than the nutes and BB.
Have fun!
I use those nutrients and have for a very long time. I would follow their feed chart but reduce their amounts and add as you see a need, as less is usually more. When I grew in NFT rails I ended up pretty close to their recommended recirculating amounts.
@OldMedUser knows his stuff.
I plan to start at 1/4 of what the feed chart recommends for nutes and calmag. My extra cautious ass will prob add 1/8 the recommended dose tomorrow and monitor the plants for 24 hours before adding the other 1/8. Wondering if I should add the calmag and nutrient mix separately to get an idea of how much each increases the ppm?
OldMedUser
Well-Known Member
I've never followed the feed rates on those charts. Use your ppm pen and go by that. I'd start at 1/4 of what they say for around 300ppm to start. Don't worry about any added ppm from the calmag but I'd go no more than half the calmag recommended on that chart.
This isn't rocket science so you don't have to be dead on the numbers. ±50 - 100ppm is close enough especially one the plants are bigger. With multiple plants on one rez the ppm drop should be up to 200 every couple days so make that up with small amounts of each nute to get back to target. Top up with water first then allow to circulate for up to an hour before checking ppm and pH then add nutes straight to the rez to get everything to target range. I would add the nutes first then allow another hour to mix well befor checking and adjusting the pH as the nutes may drop the pH quite a bit at first. I always used Rubbermaid tubs with 4+ plants per tub but just DWC not RDWC.
16 plants in that tub. Not recommended.
300ppm for the nutes or 300 for the combination of calmag and nutes? Sorry for the million questions I just want to make sure to get this right. And should I start at 1/4 the recommended calmag feeding chart or do you suggest I bump that up a bit?I've never followed the feed rates on those charts. Use your ppm pen and go by that. I'd start at 1/4 of what they say for around 300ppm to start. Don't worry about any added ppm from the calmag but I'd go no more than half the calmag recommended on that chart.
This isn't rocket science so you don't have to be dead on the numbers. ±50 - 100ppm is close enough especially one the plants are bigger. With multiple plants on one rez the ppm drop should be up to 200 every couple days so make that up with small amounts of each nute to get back to target. Top up with water first then allow to circulate for up to an hour before checking ppm and pH then add nutes straight to the rez to get everything to target range. I would add the nutes first then allow another hour to mix well befor checking and adjusting the pH as the nutes may drop the pH quite a bit at first. I always used Rubbermaid tubs with 4+ plants per tub but just DWC not RDWC.
16 plants in that tub. Not recommended.
View attachment 5319320
OldMedUser
Well-Known Member
Not critical so just add about 1/4 the max amount of nutes and 1/4 the amount of calmag to the first batch and see what it reads. Up to 400 should be just fine and it won't drop until the plants are big enough to eat a decent amount each day. Aim for around 5.6 pH but don't be anal about it. 5.4 to 6.3 is the range I aim for and if it goes up and down as you top up when it needs it so much the better. For me with large plants it was every 3 days.
Before I got the pH Perfect nutes the pH would have risen to 6.3 and I'd add a little, 4 or 5 drops, of 96% sulphuric acid to drop it down to around 5.4 then it would be back to 6.3 3 days later.
I'm going fishing so will be back in about 4 hours.
Not critical so just add about 1/4 the max amount of nutes and 1/4 the amount of calmag to the first batch and see what it reads. Up to 400 should be just fine and it won't drop until the plants are big enough to eat a decent amount each day. Aim for around 5.6 pH but don't be anal about it. 5.4 to 6.3 is the range I aim for and if it goes up and down as you top up when it needs it so much the better. For me with large plants it was every 3 days.
Before I got the pH Perfect nutes the pH would have risen to 6.3 and I'd add a little, 4 or 5 drops, of 96% sulphuric acid to drop it down to around 5.4 then it would be back to 6.3 3 days later.
I'm going fishing so will be back in about 4 hours.
Hopefully your generosity (devoting time and effort to help this newbie out) rewarded you with a stringer full of fish!.. I found this feeding chart for the nutes I will be using and the light feeding section appears to mimic the ppm levels you suggested for nutes. It states that 1.8ml gallon of each nute solution will produce a ppm of 200-300. I presume I should follow that chart? And what's the best practice when not changing out the water in the system? To mix a jug of nutes that's 200-300ppm (pre calmag) and add that to the system slowly via the resivoir?Not critical so just add about 1/4 the max amount of nutes and 1/4 the amount of calmag to the first batch and see what it reads. Up to 400 should be just fine and it won't drop until the plants are big enough to eat a decent amount each day. Aim for around 5.6 pH but don't be anal about it. 5.4 to 6.3 is the range I aim for and if it goes up and down as you top up when it needs it so much the better. For me with large plants it was every 3 days.
Before I got the pH Perfect nutes the pH would have risen to 6.3 and I'd add a little, 4 or 5 drops, of 96% sulphuric acid to drop it down to around 5.4 then it would be back to 6.3 3 days later.
I'm going fishing so will be back in about 4 hours.
Attachments
This is the feeding chart for recirculating dwc (which I have) and if my math is correct it breaks down to about 1.25ml per gallon. The other feed chart is 1.8ml per gallon to reach 200-300ppm nutes. Considering I have rdwc, should I follow the 1.25ml/g and increase if ppm too low? Also the 1.25ml/g (1/4 tsp/g) shows 5ml (1 tsp) calmag. Should I cut that calmag recommendation back as you previously advised? Or follow it as it's recommended alongside the light feeding schedule of 200-300ppm nutes?Not critical so just add about 1/4 the max amount of nutes and 1/4 the amount of calmag to the first batch and see what it reads. Up to 400 should be just fine and it won't drop until the plants are big enough to eat a decent amount each day. Aim for around 5.6 pH but don't be anal about it. 5.4 to 6.3 is the range I aim for and if it goes up and down as you top up when it needs it so much the better. For me with large plants it was every 3 days.
Before I got the pH Perfect nutes the pH would have risen to 6.3 and I'd add a little, 4 or 5 drops, of 96% sulphuric acid to drop it down to around 5.4 then it would be back to 6.3 3 days later.
I'm going fishing so will be back in about 4 hours.
Attachments
I'm re-reading thru your messages this morning and just noticed you recommended I top off the system with water than add nutes straight to the rez. Do you mean straight nute solution, not mixing the nutes together in a jug of water first then adding to rez?I've never followed the feed rates on those charts. Use your ppm pen and go by that. I'd start at 1/4 of what they say for around 300ppm to start. Don't worry about any added ppm from the calmag but I'd go no more than half the calmag recommended on that chart.
This isn't rocket science so you don't have to be dead on the numbers. ±50 - 100ppm is close enough especially one the plants are bigger. With multiple plants on one rez the ppm drop should be up to 200 every couple days so make that up with small amounts of each nute to get back to target. Top up with water first then allow to circulate for up to an hour before checking ppm and pH then add nutes straight to the rez to get everything to target range. I would add the nutes first then allow another hour to mix well befor checking and adjusting the pH as the nutes may drop the pH quite a bit at first. I always used Rubbermaid tubs with 4+ plants per tub but just DWC not RDWC.
16 plants in that tub. Not recommended.
View attachment 5319320
Nambud76
Member
Yep. I stopped changing nutes so frequently as well. At first, I just did one change--when it went to a 12/12 cycle. Now, I do two changes. I put in fresh light-levels of veg nutes post-seedling, and I maintain that until flower. I then flip to flower and change to a veg/bloom blend, and then 21-28 days into 12/12, I drain and eliminate the vast majority of nitrogen in my final flower blend. So, three nute changes throughout the entire life of the plant. It is doing as well as, if not better, than it was before, and a lot less labor and nutrients being wasted.If you have an airstone below the netpots the popping bubbles will cover any exposed roots even if they don't yet reach the water which should be about an inch below the bottom of the pots. When I would install the seedlings/clones into the system I'd just suck up some of the nute water and squirt if down the net pots once a day until roots emerged then stop top feeding.
I'd start at 300ppm which for the AN nutes was 1ml/L then as the ppm level would drop in the tub ad small amounts of nutes to keep at or raise teh ppm as the plants got bigger. I wouldn't change nutes until it was flowering time. Changing every week just throws away perfectly good nutes and makes the manufacturers of the nutes richer and you poorer. My last 20 grows or so I never changed nutes at all from start to harvest and had plants just as good. I did my first DWC in 2001 when nobody was doing it. At least nobody I'd ever heard of.
People are so overly cautious that they waste a ton instead of using common sense, and this is coming from a chemist with aseptic processing background.
OldMedUser
Well-Known Member
I ended up not going fishing. The oar locks on my oars bang back and forth which annoys me to no end and I came up with a way to fix that. After taking some measurements with my newish digital vernier caliper I figured I could get rid of that slack with some o-rings that I recently bought. By the time I finished installing them, successfully I might add, realized that by the time I loaded the car, hooked up the trailer and actually got in the water I'd maybe have an hour and a half to fish. So I spent some time gluing up the corks to make the grip for my new fly rod and clamping them to set up for shaping said grip. I plan to head out earlier today so I have 3 or 4 hours before dark which is coming earlier every day now. A month ago I could fish 'til 11 but I'll be getting out of the water shortly after 10 now.
I made the little fighting butt for the reel seat from the top grip off a crappy old 6' spin rod. My first time ever shaping cork. Not that I really need it to fight fish with but to keep the reel off the ground when the rod is standing on end. Should look good with the grip which has dark corks mixed in for something 'not off the shelf'.
The cork rings have a 1/4" hole in the middle so I have them stacked on a 1/4" ready rod with some washers on each end and thumb-screws to compress the stack while the indoor/outdoor wood glue cures for a day. I should be able to put the end of the rod in a drill chuck to spin it while shaping with files and various grades of sandpaper to get the shape I want. Going for a full wells style grip.
You might think fishing is a big hobby for me but you'd only be partially correct. It's a f'n obsession! Thanks to my paternal grandfather who got me hooked on this at the tender age of 5. I still have and fish his old fiberglass fly rod he bought in 1945 for a whole week's wages according to my dad relating his mother's bitching about the cost.
Enough about my concerns and on to yours.
Either chart will work as a jumping off point but both are predicated on a fresh batch of nutes every week and you don't want/need to be doing that. Try mixing one gallon with the recommended amount and see for certain what the ppm is. When I was doing DWC I checked the ppm in one litre after each of the 3 were added. After good veg growth is established I would change my feed from a 1-1-1 ratio to a 3-2-1 ratio, GMB, until time to flip then feed back at 1-1-1 with the addition of Big Bud to raise the P and K levels a week before the flip. Then after the stretch go to a 0-1-2 ratio to reduce the amount of N while still adding Big Bud until the end of week 5 or 6 depending on the estimated flowering time of the plants. Even longer for the 14 week sativas I used to favour.
Once your plants are growing well the ppm should drop each day as the plants use it up. When you top up with water only you can determine the daily drop by how much the ppm has dropped since last topping up. Then I would guesstimate how much of each nute to add back according to my measuring how much each adds to the total from my early measurements of how much each raises the ppm. I have a variety of syringe sizes and would use them to accurately measure out each nute to squirt into the tub to bring my ppm back to my target range. No pre-mixing with water needed unless using powdered nutes which would need weighing on a scale to get accurate results.
If you're aiming for 300 and get 250 - 350 then it's all good. Overfeeding should be avoided as too high levels will cause accumulation of nutrient salts in the leaves of the plants over time which leads to toxic salts buildup that will fry your plants as they finish flowering. Too much P in later flowering results in that 'chem' taste in the buds when smoked. Best to be a bit low on the feed and if you notice yellowing in older fan leaves up the ppm 10% when you next add nutes. Less is more when growing nice clean tasting buds. In the last 2 or 3 weeks of flowering I want to see older fan leaves going yellow and limp. That indicates the plant is relocating some mobile nutes to feed the fattening buds and won't be tasting bad.
Save these for later reference.
OldMedUser
Well-Known Member
I often wonder if my outcomes from growing in a hydro system is better than what I can do in dirt is from going back to school in my 30s to get a diploma in environmental chemistry. Probably more from my mom teaching me to cook and knowing how to accurately measure ingredients to have the next cake turn out the same as the previous cake.
Growing pot is a lot like raising kids. You obsess about the first one, worry about the 2nd one but by the time the 3rd one comes along you are a lot more relaxed about it all. Unless of course you are OCD then it's all a hellish existence.
Thank you, thank you, thank you! Sorry I haven't been able to respond yet, life has been crazy the last few days.I ended up not going fishing. The oar locks on my oars bang back and forth which annoys me to no end and I came up with a way to fix that. After taking some measurements with my newish digital vernier caliper I figured I could get rid of that slack with some o-rings that I recently bought. By the time I finished installing them, successfully I might add, realized that by the time I loaded the car, hooked up the trailer and actually got in the water I'd maybe have an hour and a half to fish. So I spent some time gluing up the corks to make the grip for my new fly rod and clamping them to set up for shaping said grip. I plan to head out earlier today so I have 3 or 4 hours before dark which is coming earlier every day now. A month ago I could fish 'til 11 but I'll be getting out of the water shortly after 10 now.
I made the little fighting butt for the reel seat from the top grip off a crappy old 6' spin rod. My first time ever shaping cork. Not that I really need it to fight fish with but to keep the reel off the ground when the rod is standing on end. Should look good with the grip which has dark corks mixed in for something 'not off the shelf'.
View attachment 5319570View attachment 5319580
The cork rings have a 1/4" hole in the middle so I have them stacked on a 1/4" ready rod with some washers on each end and thumb-screws to compress the stack while the indoor/outdoor wood glue cures for a day. I should be able to put the end of the rod in a drill chuck to spin it while shaping with files and various grades of sandpaper to get the shape I want. Going for a full wells style grip.
View attachment 5319571
You might think fishing is a big hobby for me but you'd only be partially correct. It's a f'n obsession! Thanks to my paternal grandfather who got me hooked on this at the tender age of 5. I still have and fish his old fiberglass fly rod he bought in 1945 for a whole week's wages according to my dad relating his mother's bitching about the cost.
Enough about my concerns and on to yours.
Either chart will work as a jumping off point but both are predicated on a fresh batch of nutes every week and you don't want/need to be doing that. Try mixing one gallon with the recommended amount and see for certain what the ppm is. When I was doing DWC I checked the ppm in one litre after each of the 3 were added. After good veg growth is established I would change my feed from a 1-1-1 ratio to a 3-2-1 ratio, GMB, until time to flip then feed back at 1-1-1 with the addition of Big Bud to raise the P and K levels a week before the flip. Then after the stretch go to a 0-1-2 ratio to reduce the amount of N while still adding Big Bud until the end of week 5 or 6 depending on the estimated flowering time of the plants. Even longer for the 14 week sativas I used to favour.
Once your plants are growing well the ppm should drop each day as the plants use it up. When you top up with water only you can determine the daily drop by how much the ppm has dropped since last topping up. Then I would guesstimate how much of each nute to add back according to my measuring how much each adds to the total from my early measurements of how much each raises the ppm. I have a variety of syringe sizes and would use them to accurately measure out each nute to squirt into the tub to bring my ppm back to my target range. No pre-mixing with water needed unless using powdered nutes which would need weighing on a scale to get accurate results.
If you're aiming for 300 and get 250 - 350 then it's all good. Overfeeding should be avoided as too high levels will cause accumulation of nutrient salts in the leaves of the plants over time which leads to toxic salts buildup that will fry your plants as they finish flowering. Too much P in later flowering results in that 'chem' taste in the buds when smoked. Best to be a bit low on the feed and if you notice yellowing in older fan leaves up the ppm 10% when you next add nutes. Less is more when growing nice clean tasting buds. In the last 2 or 3 weeks of flowering I want to see older fan leaves going yellow and limp. That indicates the plant is relocating some mobile nutes to feed the fattening buds and won't be tasting bad.
Save these for later reference.
View attachment 5319594
View attachment 5319595
View attachment 5319596
I just spotted these brown spots on the lower leaves of one of the girls before heading out to work. Is this calcium deficiency? I only started with 1/4 the recommendation for calmag. Based off the accuracy of the feed chart turning out to be 25% nutes for week one, I'm wondering if the recommended amount of calmag for week one is correct? I'm guessing if it's calcium deficiency you will advise upping the calmag to 50% and monitoring before adding more? If so how long do I monitor before going above 50%? Again, sorry I haven't had time to sit back and respond to the incredibly helpful info you shared.
Edit: Well, turns out it's not calcium deficiency as it's showing in the lower leaves. Any idea what could be causing those brown spots?
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Well, turns out it's not calcium deficiency as it's showing in the lower leaves.
OldMedUser
Well-Known Member
A couple of pictures would help. Low Mg or K can cause spots but have other signs to help pinpoint the possible cause.
Oops! Here is a couple pics. The last pic is a zoom in on a couple tan spots that are darker. The white dots were determined to be early trichombs by rubbing and smelling my finger. Another user said the trichs may be present because it's a pest resistant strain or because of a calcium shortage. The tan spots are only on the lowest set of leaves, the first true leaves.A couple of pictures would help. Low Mg or K can cause spots but have other signs to help pinpoint the possible cause.
