RDWC - TopOff (steering vs water change)

[Medigrow]

Hey everyone! :)

I was wondering what is the best way to drive the system, efficiency wise. Is it better to simply topoff with RO water (letting the system's nutrient fall down) and do a water change frequently or it's better to steer the system using the topoff with a tailored solution to keep the system's nutrient level? My system drinks like crazy and I noticed that everytime I do a water change, all the ladies really like it. System is drinking 30 to 40 liters a day...

Example: system was at 580 ppm, topoff at 550 and 18 hours later, system was at 500!

Is it better to maintain nutrient level or do a water change every 3-4 days? I'm wondering because of the nutrients it requires each day to maintain the topoff at the required strength is barely the same quantity a full water change would require..

Thank you for every input/though/suggestion/trivia/pictures! :DDD

 

[Medigrow]

Anyone?

 

[Scolymia7]

Not sure if it is correct but I do both. I top with R.O. water until ppm drops to 700ish from 1300. If the water doesnt smell, surface of pumps, probes, or air stones arent slimy I add nutrients to bring ppm back to 1300ish. Clean or not I do water changes every 3 weeks. I started doing this accidently when I got my blue lab ph/ppm probe. As the ppm changed the ph did as well, I read somewhere(probally here) it's good to let your ppm bounce between 5.4 and 5.8 in hydro, with ppm slowly dropping and me topping off with R.O. ph did just that. So I developed a routine based around that and my girls haven't complained. Seeing as you run ppms alot lower than I do, it may be in your best interest to maintain that ppm. I dont know what nutrients you are using but 540 seems low to me. My system has 6 plants and I've seen them drink up 3-400 ppm in one evening. I usually do a nutrient top off every other day during those weeks of flower when they are fattening.

Hope that helps :)

 

[Medigrow]

Not sure if it is correct but I do both. I top with R.O. water until ppm drops to 700ish from 1300. If the water doesnt smell, surface of pumps, probes, or air stones arent slimy I add nutrients to bring ppm back to 1300ish. Clean or not I do water changes every 3 weeks. I started doing this accidently when I got my blue lab ph/ppm probe. As the ppm changed the ph did as well, I read somewhere(probally here) it's good to let your ppm bounce between 5.4 and 5.8 in hydro, with ppm slowly dropping and me topping off with R.O. ph did just that. So I developed a routine based around that and my girls haven't complained. Seeing as you run ppms alot lower than I do, it may be in your best interest to maintain that ppm. I dont know what nutrients you are using but 540 seems low to me. My system has 6 plants and I've seen them drink up 3-400 ppm in one evening. I usually do a nutrient top off every other day during those weeks of flower when they are fattening.

Hope that helps :)

I'm using CS's line... and at 530-540, I can see the tip of the leaves burning a little... Sweet spot is at 400-450ppm top :)

700 to 1300? What is your air input vs gal ?

 

[LWGT]

The "change your water every 2 weeks" rule is waste of time and money. Nutes are way too expensive. Watch your ppm and feed accordingly.
Your example: system was at 580 ppm, topoff at 550 and 18 hours later, system was at 500!
So...you have a fresh system/reservoir full of a mixture of 580 ppm. This system runs for 3 days and now needs watering, what do you do?
Example 1: in 3 days your ppm is still 580 then feed/fill reservoir with exactly what you did when you initially filled the system with, it will stay at 580
Example 2: in 3 days your ppm is 1160 then feed/fill reservoir with just plain water.
Example 3: in 3 days your ppm is 290 then feed/fill reservoir with 870

It's all about dialing in your system and paying attention to your plants...they will tell you what they need. Keep in mind that there are times when complete change-outs are needed. If your plants run into a problem (mainly nute deficiency) it is best to do a change-out to correct the problem as soon as possible. If your ph starts to fluctuate a lot sometimes this merits change-out. The flip from 18 to 12 also needs a change-out to kick start the flower stage. I also do a change-out when I flush (1-2 weeks prior to harvest) but that's optional as well.

The RDWC is a little tricky at first, but when you get her dialed in it's a beautiful thing. Plus you get to watch your plants grow twice as fast as the dirt farmers bahahaha... seriously though, it's actually less work and cheaper in the long run to maintain.

Hope this helps and happy growing

 

[lrfowler]

The "change your water every 2 weeks" rule is waste of time and money. Nutes are way too expensive. Watch your ppm and feed accordingly.
Your example: system was at 580 ppm, topoff at 550 and 18 hours later, system was at 500!
So...you have a fresh system/reservoir full of a mixture of 580 ppm. This system runs for 3 days and now needs watering, what do you do?
Example 1: in 3 days your ppm is still 580 then feed/fill reservoir with exactly what you did when you initially filled the system with, it will stay at 580
Example 2: in 3 days your ppm is 1160 then feed/fill reservoir with just plain water.
Example 3: in 3 days your ppm is 290 then feed/fill reservoir with 870

It's all about dialing in your system and paying attention to your plants...they will tell you what they need. Keep in mind that there are times when complete change-outs are needed. If your plants run into a problem (mainly nute deficiency) it is best to do a change-out to correct the problem as soon as possible. If your ph starts to fluctuate a lot sometimes this merits change-out. The flip from 18 to 12 also needs a change-out to kick start the flower stage. I also do a change-out when I flush (1-2 weeks prior to harvest) but that's optional as well.

The RDWC is a little tricky at first, but when you get her dialed in it's a beautiful thing. Plus you get to watch your plants grow twice as fast as the dirt farmers bahahaha... seriously though, it's actually less work and cheaper in the long run to maintain.

Hope this helps and happy growing

 

[lrfowler]

"""So...you have a fresh system/reservoir full of a mixture of 580 ppm. This system runs for 3 days and now needs watering, what do you do?
Example 1: in 3 days your ppm is still 580 then feed/fill reservoir with exactly what you did when you initially filled the system with, it will stay at 580...."""

It will stay at 580 if I add the same amount I added initially?...the PPM doesn't increase?

 

[Medigrow]

"""So...you have a fresh system/reservoir full of a mixture of 580 ppm. This system runs for 3 days and now needs watering, what do you do?
Example 1: in 3 days your ppm is still 580 then feed/fill reservoir with exactly what you did when you initially filled the system with, it will stay at 580...."""

It will stay at 580 if I add the same amount I added initially?...the PPM doesn't increase?

It will depends on a lot of things.

Usually, when I was using a topoff full a nutes, I had to make it way stronger than the actual rdwc solution. Let's say I was running the system at 450 ppm, the topoff was at 650-800, even more sometimes.

I wasn't able to get past through 450 ppm (tips were burning) but they consumed nutes like crazy so I had to adjust my topoff accordingly.

Let's start with system at 400, TO at 500 and see how it goes, if ppm raises, then the TO is too strong. If it drops, not strong enough.