I need help quick with my new DWC set up.

Irollfatties

Irollfatties

Active Member
So i have 5 five gallon set up which includes the controller with a 250gph pump. 1/4in feed lines and 3/4 returns. So first off i was testing the system and i poured about 17.5 gallons total,about 3.5 in each one. Well everything looked and worked great so my dumbass starts to pour nutes into the controller. Once the deed was done i then realize this thing is gonna take forever to equalize before i can put my plants in. So i make shift a huge rubbermaid and pump the mixed water into that. All good right? so i pump it back. Drop only 2 plants in because i don't have two other airstones and realize the ph will need adjusting. FUCK!!! I check and its roughly 6.1-6.3 or so my question is how long do you think it will take to mix completely around. I poured only a couple ML of ph down in the controll bucket because i'm scared it will suck directly into the two with plants and could become to acidic.

So to sum it all up how long do you think it will take for ph down to make it all the way around to all four buckets(remember only 2 have airstones and plants til tomorrow), or if its even possible?

thanks
 
drgreentm

drgreentm

Well-Known Member
at 250 gallons per hour i would say in a hour it would be plenty of time to take another accurate ph reading. prably allot sooner than that if you wanted to check it sooner. this is a recirculating dwc correc??
 
J

jsgamber

Active Member
Irollfatties said:
Yeah, it's recirculating
Click to expand...
The pH will change over time at a linear rate until it reaches equilibrium. What you need to determine is what that rate is. First take an initial pH reading. Then take a measured amount of pH down and add it into the reservoir. Take a reading at 5 minutes and at 10 minutes. This will give you the approximate rate of change, over time for a particular amount of pH down. Continue taking readings and once you get two consecutive readings that are the same within 5 minutes, you can assume it has stabilized. Record the time of the first stable reading and you know how long you have to wait any time you add anything new into the reservoir before you know it's properly mixed.

Realize that having air stones in a water tank will change the rate of the mix so plan accordingly.

:peace:
 
Irollfatties

Irollfatties

Active Member
jsgamber said:
The pH will change over time at a linear rate until it reaches equilibrium. What you need to determine is what that rate is. First take an initial pH reading. Then take a measured amount of pH down and add it into the reservoir. Take a reading at 5 minutes and at 10 minutes. This will give you the approximate rate of change, over time for a particular amount of pH down. Continue taking readings and once you get two consecutive readings that are the same within 5 minutes, you can assume it has stabilized. Record the time of the first stable reading and you know how long you have to wait any time you add anything new into the reservoir before you know it's properly mixed.

Realize that having air stones in a water tank will change the rate of the mix so plan accordingly.


:peace:
Click to expand...
Thanks for your help. Did you mean pour measured ph down in the control bucket. Then take a reading at the actual buckets my plants are in at 5 min and then at 10min? I just wonder how it will flow since i pour ph down in the control which has the pump at the bottom right next to the return lines. So in essence it could be sucking up the "other un ph'd" (only way i could explain it) nutes before it sucks the ph'd nutes in the control bucket. I hope that makes sense.

The 1/4 in lines move the water back really slowly. I had to switch out a bucket today becuase it was leaking at the bulkhead and i grabbed the `1/4 hose and started filling up a huge rubbermaid. It took nearly 45 min and only probably took half of the 17.5 gallons. I only mention this becuase i think it could possibly take a long time to equalize.
 
J

jsgamber

Active Member
Irollfatties said:
Thanks for your help. Did you mean pour measured ph down in the control bucket. Then take a reading at the actual buckets my plants are in at 5 min and then at 10min? I just wonder how it will flow since i pour ph down in the control which has the pump at the bottom right next to the return lines. So in essence it could be sucking up the "other un ph'd" (only way i could explain it) nutes before it sucks the ph'd nutes in the control bucket. I hope that makes sense.

The 1/4 in lines move the water back really slowly. I had to switch out a bucket today becuase it was leaking at the bulkhead and i grabbed the `1/4 hose and started filling up a huge rubbermaid. It took nearly 45 min and only probably took half of the 17.5 gallons. I only mention this becuase i think it could possibly take a long time to equalize.
Click to expand...
Without pictures, I need to make a lot of assumptions. So let me give some info to help you figure things out.

Regarding pH and DWC. Optimal pH is 5.8. However, your plants take up different nutrients at varying pH levels so fluctuations in pH is definitely a good thing (nature does this by making it rain)! If your pH is anywhere between 5.5 and 6.5 then don't even sweat! If you want to get back towards the 5.8 mark, then only make adjustments of no more than .4 in a 12 hour period. Never chase pH.

First off, you now know rate of flow: ((17.5 / 2 ) / 45) * 60 = 12 GPH. With 5 buckets you are utilizing 12 * 5 = 60GPH of your 250GPH pump capacity (roughly).

So at 12 GPH you should be getting one full 5 gallon exchange in each bucket every 25 minutes.

Now one piece of missing information is how many gallons of water is in your control bucket? For sake of argument and simplification let's assume you have a 25 gal control bucket in addition to the 5 buckets * 5 gallons each = 25 gallons or 50 total gallons in your system.

Next you need to know the rate of pH adjustment for your water. Different water types will change differently based on the buffers present, for example in tap water vs. R/O or distilled water. For me .5ml of pH down will drop my pH by .4 in 2 gallons of water, each time!! If you were using 50 gallons of my tap water, you would need roughly 12.5ml of pH down to bring your entire system down by .4.

Let's do an example based on 50 gallons total; 25 in the control and 5 in 5 buckets. You've tested the pH throughout the system including the control bucket and plant buckets all read 6.6 consistently (if this isn't the case, you have issues). So you want to drop by .4. You know 12.5ml of pH down will do the trick or get you close. Pour the pH down into your control bucket and stir it up (keeping an air stone running in your control bucket will help this too). The control tank should instantly drop from 6.6 to 5.8 (twice your target). Within 25 minutes, your flow rate for one 5 gallon bucket exchange should equalize the entire system to your target 6.2.

All of these basic calculations and ratios work just the same for PPM and nutes! You just need to adjust the ratios based on your control bucket capacity and total gallons in the system. Once you figure out your ratios and flow rates, write them down and even make a chart in the event you want to add more buckets to the system.

I hope this was helpful.

:peace:
 
J

jsgamber

Active Member
Irollfatties said:
I'll respond back tomorrow when I'm not as fucked up. Thanks in advance.
Click to expand...
:lol: I was fucked up when I wrote it! Hopefully you'll understand it! :lol:

Seriously it's all fractions and percentages. We are working with chemical solutions; not chemical reactions.

One other very important procedure you must adopt! Never add chemicals straight into your control bucket. Take a clean bucket and measure out 1 to 5 gallons of water from your control tank and add chemicals to that, test and verify before pouring it back into the control tank. It's much easier to throw away 5 gallons of fucked up water rather then 50 gallons after putting in 1 cup of pH down thinking it was Boost Nutes because you were baked and they have the same color! :shock:

Ask if you have any questions!

:peace:
 
Irollfatties

Irollfatties

Active Member
jsgamber said:
Without pictures, I need to make a lot of assumptions. So let me give some info to help you figure things out.

Regarding pH and DWC. Optimal pH is 5.8. However, your plants take up different nutrients at varying pH levels so fluctuations in pH is definitely a good thing (nature does this by making it rain)! If your pH is anywhere between 5.5 and 6.5 then don't even sweat! If you want to get back towards the 5.8 mark, then only make adjustments of no more than .4 in a 12 hour period. Never chase pH.

First off, you now know rate of flow: ((17.5 / 2 ) / 45) * 60 = 12 GPH. With 5 buckets you are utilizing 12 * 5 = 60GPH of your 250GPH pump capacity (roughly).

So at 12 GPH you should be getting one full 5 gallon exchange in each bucket every 25 minutes.

Now one piece of missing information is how many gallons of water is in your control bucket? For sake of argument and simplification let's assume you have a 25 gal control bucket in addition to the 5 buckets * 5 gallons each = 25 gallons or 50 total gallons in your system.

Next you need to know the rate of pH adjustment for your water. Different water types will change differently based on the buffers present, for example in tap water vs. R/O or distilled water. For me .5ml of pH down will drop my pH by .4 in 2 gallons of water, each time!! If you were using 50 gallons of my tap water, you would need roughly 12.5ml of pH down to bring your entire system down by .4.

Let's do an example based on 50 gallons total; 25 in the control and 5 in 5 buckets. You've tested the pH throughout the system including the control bucket and plant buckets all read 6.6 consistently (if this isn't the case, you have issues). So you want to drop by .4. You know 12.5ml of pH down will do the trick or get you close. Pour the pH down into your control bucket and stir it up (keeping an air stone running in your control bucket will help this too). The control tank should instantly drop from 6.6 to 5.8 (twice your target). Within 25 minutes, your flow rate for one 5 gallon bucket exchange should equalize the entire system to your target 6.2.

All of these basic calculations and ratios work just the same for PPM and nutes! You just need to adjust the ratios based on your control bucket capacity and total gallons in the system. Once you figure out your ratios and flow rates, write them down and even make a chart in the event you want to add more buckets to the system.

I hope this was helpful.

:peace:
Click to expand...
Wow, you must be very smart if you could right/think that while you were fucked up. I'm still fucked up,, my friend Molly stopped by to have a threesome with me and my GF. I'm still chillin with her. :)

Anyway to answer the obvious question i saw in your post is the control bucket is a 5 gallon as well. I might change that out with a bigger rubbermaid in the future. I'm using tap water becuase i am fortunate to have a very low PPM which is 120 on .5 meter. I can't remember the ph but i wanna say its around 7.5-7,8.

Once i mix the nutes (Lucas Formula which i'm not too impressed with yet because i'm having some issue) comes out to around 6.5 ish. I just recently broke my meter for good but its okay because it was off. When my meter read 5.8 i tested the ph with the liquid test and it was over 6.0 prob 6.3. I'm probably not gonna buy another one til harvest which should be around 50 or so days. So hopefully the liquid test will get me by.I'm trying to keep the res right at 6 or 6.1.

And lastly i think i was short a couple gallons when i started out with 17.5. That was all the water i had out sitting for a day to let the chlorine evaporate. Can you explain the numbers agan in your post. Where did you get the 45 from? Thanks again and sorry if there is some gramatical/rambling issues in this post as i'm still pretty trashed.
 
J

jsgamber

Active Member
Irollfatties said:
Wow, you must be very smart if you could right/think that while you were fucked up. I'm still fucked up,, my friend Molly stopped by to have a threesome with me and my GF. I'm still chillin with her. :)

Anyway to answer the obvious question i saw in your post is the control bucket is a 5 gallon as well. I might change that out with a bigger rubbermaid in the future. I'm using tap water becuase i am fortunate to have a very low PPM which is 120 on .5 meter. I can't remember the ph but i wanna say its around 7.5-7,8.

Once i mix the nutes (Lucas Formula which i'm not too impressed with yet because i'm having some issue) comes out to around 6.5 ish. I just recently broke my meter for good but its okay because it was off. When my meter read 5.8 i tested the ph with the liquid test and it was over 6.0 prob 6.3. I'm probably not gonna buy another one til harvest which should be around 50 or so days. So hopefully the liquid test will get me by.I'm trying to keep the res right at 6 or 6.1.

And lastly i think i was short a couple gallons when i started out with 17.5. That was all the water i had out sitting for a day to let the chlorine evaporate. Can you explain the numbers agan in your post. Where did you get the 45 from? Thanks again and sorry if there is some gramatical/rambling issues in this post as i'm still pretty trashed.
Click to expand...
Let's just say I spend a lot of time watching Discovery, Science Channel, History Channel, NatGeo just to name a few. I just love anything science. Even though I was a business major, I sat in with all the ARCH, ARCHE, EE, PHYS majors to take 2 semesters of Chemistry, 2 semesters of Physics and 1 semester of biology to fulfill my General Electives...all A's. Most people take basket weaving and "Earth Science". :lol: I've also downloaded two semesters worth of Astonomy podcasts from Richard Pogge at Ohio State. I have an 8" Newtonian so you can see me gazing up at the skies on every camping trip!

The 45 is minutes. You said about 3/4 of an hour (45 min) to halfway fill 17.5 gallons or 17.5/2 = 8.75 gallons in 45 minutes. I just converted to one hour for standardization.

((17.5 gal/ 2 ) / 45 min) * (60 min/1 hour) = 12 GPH. which is roughly the rate of flow for your 250GPH pump running through 1/4" tubing.

With a 5 gallon control bucket replace the 50 gallons total with 30 gallons.

As long as your pH stays between 5.5 and 6.5 and you shoot for adjustments back to 5.8 to 6.0 you shouldn't sweat it as long as the swings are within .4 to .6 per day.

Whoa I'm starting to not make sense! I better go bongsmilie bongsmilie bongsmilie bongsmilie

:lol:

Read and ask. I'll be here and if I can't answer you, I'll track someone down who can!

:peace:
 
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