best way to do a resivour change DWC
- Thread starter ckckck
- Start date
blakkmask
Well-Known Member
How about instead of changing you res, you use the LUCAS FORMULA, no res change method.
General Hydroponics Flora Series Feeding Strategy - Lucas Formula
G-M-B (Grow-Micro-Bloom)
0-5-10 - For Vegetative cycle (18/6)
0-8-16 - For Flowering cycle (12/12)
The numbers above indicate the number of milliliters (ml) of Flora Grow, Micro or Bloom formulas that I use in one gallon (US Liquid) of nutrients.
You will notice I dont use any of the Flora Grow formula, do not need to, the Flora "Micro" provides plenty of Nitrogen.
There are two ways to work with this formula:
1. Top off the reservoir daily using a pH corrected water solution as required to maintain full reservoir level. After adding back an amount of water equal to the amount of your reservoir capacity you should change the reservoir and put in fresh solution.
2. Top off the reservoir daily using a pH corrected 100% strength nutrient solution as required to maintain full reservoir level. Continue to use this nutrient solution without dumping the tank unless the PPM rises above acceptable levels.
Between vegetative and flowering cycles you should dump your nutrients, then flush (possibly with Clearex) to remove salt buildups, then change to the other feeding program. Always shake your GH nutrient bottles before using them!
For young plants, just transplanted into the hydro setup, give them 50% strength nutrient mix to prevent overfeeding them while their young. Gradually bring up the mix to full strength as they grow over the next few weeks or so.
The lucas formula is normally intended for use with RO or near 0 PPM water.
NOTE: The Lucas formula eliminates the need for Epsom salts to correct (Magnesium) Mg deficiencies in most normal feeding programs recommended by manufacturers. Cannabis needs a lot of Magnesium to thrive.
The Flora Micro is providing the Nitrogen and the Magnesium in the proper balance, thus there is no need for the Grow formula and little or no room under the maximum acceptable ppm limit of 1600 @ 0.7 conversion.
Calculated EC/TDS levels:
EC microsiemen:
0-4-8: 946 µS
0-5-10: 1184 µS
0-8-16: 1894 µS
TDS @ 0.5 conversion:
0-4-8 = 473 ppm
0-5-10 = 592 ppm
0-8-16 = 947 ppm
TDS @ 0.7 conversion:
0-4-8 = 663 ppm
0-5-10 = 829 ppm
0-8-16 = 1326 ppm
Addback Calculator - (For Advanced Users)
Say you were running the 0-8-16 formula, at 0.7 conversion with a 22 gallon res. When you first fill it up, your ppm will be around 1330.
Now you have been growing for a week, and some of the water has been taken up by the plants, some has evaporated, and now your res is at 947 ppm. You need to get your ppm from 947 to 1330. Here is the equation:
((target - current) / target) * 8 ml per gallon * res gallons = Flora Micro (ml) double this figure to get Flora Bloom (ml)
Example:
((1330 - 947) / 1330) * 8 * 22
(383 / 1330) * 8 * 22
0.3 * 8 * 22 = 53 ml Flora Micro
53 ml Flora Micro, double that and you get 106 ml Flora Bloom. So 53 ml Flora Micro and 106 ml Flora Bloom to add back to your 22 gallon res to get you from 947 to 1330.
Using Hard Water GH Micro
I had been experimenting with using the Hard water Micro as a substitute for the normal Flora Micro, this to account for my hard 350 PPM water and the lack of a large enough RO filter at the time. It has worked well for me. I just kept my reservoir below 1150 PPM @ .5 conversion and its all good.
One tip - do not pH down this stuff, the hard water micro will drop pH gradually over the next 24 hours, for example I mix up a batch, it is at like 6.2, the next day, its at 5.6-5.8 after running in the system for a while. If I pH downed that to 5.7 before putting it in the system, it ended up as low as 4.8-5.2 by the next day.
My conclusion, the hard water micro was buffering the alkaline crud in my water, it just doesnot do it ASAP fast like the phosphoric acid.
General Hydroponics Flora Series Feeding Strategy - Lucas Formula
G-M-B (Grow-Micro-Bloom)
0-5-10 - For Vegetative cycle (18/6)
0-8-16 - For Flowering cycle (12/12)
The numbers above indicate the number of milliliters (ml) of Flora Grow, Micro or Bloom formulas that I use in one gallon (US Liquid) of nutrients.
You will notice I dont use any of the Flora Grow formula, do not need to, the Flora "Micro" provides plenty of Nitrogen.
There are two ways to work with this formula:
1. Top off the reservoir daily using a pH corrected water solution as required to maintain full reservoir level. After adding back an amount of water equal to the amount of your reservoir capacity you should change the reservoir and put in fresh solution.
2. Top off the reservoir daily using a pH corrected 100% strength nutrient solution as required to maintain full reservoir level. Continue to use this nutrient solution without dumping the tank unless the PPM rises above acceptable levels.
Between vegetative and flowering cycles you should dump your nutrients, then flush (possibly with Clearex) to remove salt buildups, then change to the other feeding program. Always shake your GH nutrient bottles before using them!
For young plants, just transplanted into the hydro setup, give them 50% strength nutrient mix to prevent overfeeding them while their young. Gradually bring up the mix to full strength as they grow over the next few weeks or so.
The lucas formula is normally intended for use with RO or near 0 PPM water.
NOTE: The Lucas formula eliminates the need for Epsom salts to correct (Magnesium) Mg deficiencies in most normal feeding programs recommended by manufacturers. Cannabis needs a lot of Magnesium to thrive.
The Flora Micro is providing the Nitrogen and the Magnesium in the proper balance, thus there is no need for the Grow formula and little or no room under the maximum acceptable ppm limit of 1600 @ 0.7 conversion.
Calculated EC/TDS levels:
EC microsiemen:
0-4-8: 946 µS
0-5-10: 1184 µS
0-8-16: 1894 µS
TDS @ 0.5 conversion:
0-4-8 = 473 ppm
0-5-10 = 592 ppm
0-8-16 = 947 ppm
TDS @ 0.7 conversion:
0-4-8 = 663 ppm
0-5-10 = 829 ppm
0-8-16 = 1326 ppm
Addback Calculator - (For Advanced Users)
Say you were running the 0-8-16 formula, at 0.7 conversion with a 22 gallon res. When you first fill it up, your ppm will be around 1330.
Now you have been growing for a week, and some of the water has been taken up by the plants, some has evaporated, and now your res is at 947 ppm. You need to get your ppm from 947 to 1330. Here is the equation:
((target - current) / target) * 8 ml per gallon * res gallons = Flora Micro (ml) double this figure to get Flora Bloom (ml)
Example:
((1330 - 947) / 1330) * 8 * 22
(383 / 1330) * 8 * 22
0.3 * 8 * 22 = 53 ml Flora Micro
53 ml Flora Micro, double that and you get 106 ml Flora Bloom. So 53 ml Flora Micro and 106 ml Flora Bloom to add back to your 22 gallon res to get you from 947 to 1330.
Using Hard Water GH Micro
I had been experimenting with using the Hard water Micro as a substitute for the normal Flora Micro, this to account for my hard 350 PPM water and the lack of a large enough RO filter at the time. It has worked well for me. I just kept my reservoir below 1150 PPM @ .5 conversion and its all good.
One tip - do not pH down this stuff, the hard water micro will drop pH gradually over the next 24 hours, for example I mix up a batch, it is at like 6.2, the next day, its at 5.6-5.8 after running in the system for a while. If I pH downed that to 5.7 before putting it in the system, it ended up as low as 4.8-5.2 by the next day.
My conclusion, the hard water micro was buffering the alkaline crud in my water, it just doesnot do it ASAP fast like the phosphoric acid.
ckckck
Active Member
well this is my 1st grow i have a ro unit that produces o tds water i was going to use canna aqua veg and canna aqua flower along with pk13/14 and cannazym so do u recomend using the above nutrient that you mentioned i was thinking about using aother resiviour and just do the swap over does the water need to be the same temp as the old water
cheers for ur help
blakkmask
Well-Known Member
GH (General Hydroponics) is a vary good nutrient line and up until a few years back, was the gold standard for hydro. And although some have moved on to other companies, GH is still one of the best, user friendly, customizable nutrient lines on the market. Actually, you could also use Advanced Nutrients becuz they were designed to be similar to the GH 3 Part; or any GROW, MICRO, BLOOM 3 Part ferts similar is NPK levels, But remember, all you need is the bloom and micro parts for the Lucas Formula. As far water temp, just make sure its about room temp, too hot or too cold could shock your girlz.
treeburner
Member
Hey there.
I would just change your reservoir and your buckets every seven to ten days when the plants are young and smaller.
So all I do is to dump the buckets, but I don't top off the nute water at all.
I clean out the buckets a bit and then get some distilled water and make a nutrient solution that's pH adjusted.
The problem with topping off the nutrients is that sometimes that can make it too easy to have to deal with nute burn.
I also find that Advanced Nutrients has been the best for my nute needs, without causing troubles with pH and all that stuff.
Hope that helps - just some basic tips, but it's pretty easy.
tip top toker
Well-Known Member
have 2 totes. one with the plants and old feed, other with fresh batch of feed in it all ready. take lid off first tote, take care of roots, put on second res. pour first res into the bath and clean.
Sgt Pepper
Member
I kind of do a lucas method but with technaflora.
I have an aquarium siphon and fill. Its 25ft and hooks to a sink or garden hose. drains it, then you can fill it, but I use it just to drain (if I change it)
Ringo
I have an aquarium siphon and fill. Its 25ft and hooks to a sink or garden hose. drains it, then you can fill it, but I use it just to drain (if I change it)
Ringo
rickymac21
Well-Known Member
I know this thread is a little older but I would have to say I like this idea best.... I feel like it would be pretty simple.. Just pop the container lid off, siphon the water out... clean it up, then put in some fresh ph'd water for a day or so to flush old nutes, then siphon again, and then add new ph'd water with nute mix... just sounds like the most efficient way of accomplishing a pretty effective flush/nute change.
Weedler
Well-Known Member
I bought a bilge pump that runs off a deer feeder battery it will pump the 4GA in my team sports cooler out real fast. I drain the rest into a small tray through the dispenser built in. Once rinsed out and drained again I go over to my premixed nutrient solution and place the pump in the bucket, pump into reservoir... repeat.
onthedl0008
Well-Known Member
Get urself a small submersible pump and attach a piece of half inch clear tubeing to it. Drop it in. Pump it out into a seperate container. I always cut an extra hole just for maintenace adding nutez. topping Off. Rez changes etc. As already mentioned rez changes arent even totally necessary. Ive grown a plant from start to finish without changeing my rez once. I do rez changes according to the stage of growth my plants are in to change the ratios of specific nutes im feeding my plants during different stages of flowering. Hope that helps with ur original question tho. U can rig up a small pump and piece of hose for like ten bux tho. Peace.
***Deftoned***
Member
Im using advanced nutrients as well. GREAT STUFFF. supernaturals grow and bloom aqua. I use distilled water and i dont even check my ph/ppm/.
BigBuddahCheese
New Member
get a bucket head and get it changed in few minutes.. 20 bucks at Lowes or HomeDepot.. best investment I ever made.
onthedl0008
Well-Known Member
Sure its already been said but get a submersible pump and enuff tubeing to reach ur nearest drain and pump it out.
S. African grower
Well-Known Member
I have the submersible pump and tubing and everything.. Draining the water is not my problem.. But can the roots sit dry in the res while I'm changing over to fresh nutes?
S. African grower
Well-Known Member
Thank you so much for this detailed response, I do greatly appreciated it
futurebanjo
Well-Known Member
Yes, I did this.
Submersible pump powerfull enough to pump through 10 meters of hose, into the bathtub in the room next door.
Once drained, I fill the bathtub up with water and mix a nute solution in to the correct volume to fill the res.
Reverse the apperatus and pump the fresh nute solution back to the res.
My pump is not that powerfull so it takes about 40 mins to drain the res, then say maybe another 1.5hrs to mix, adjust and pump fresh solution back to the res.
The roots won't dry out to the point they are damaged for a good few hours easily.
My res holds 28 gallons of nutes and I use a 5 gallon per minute sump pump. In short, I mix the nutes in a 32 gallon trash can, pump out the res, and then pump the nutes from the trash can into the res.
I do not top up the way the OP has recommended. That approach may lead to nutrient issues because the chemicals in nutrient solution are taken up at very different rates. If you keep adding fresh nutrient solution to a res, you will run the risk of plants getting excess of those nutrients that have been depleted. For example, NO3, NH4, P, K, Mn are taken up very quickly, within a matter of hours. If you top off your res with fresh nutes, you're adding more and more of those chemicals even though they're already in the plant.
If you can analyze lead tissue to determine what specific chemicals need to be added, then add those. Lacking that, the most safe approach is to top up with RO ("add backs") until you've replaced 50% of your res volume or if the res is showing signs of pH instability. That instability is an indictor that the nutrient solution is no longer able to buffer the electrical imbalance caused by nutrient exhaustion and the reservoir should be replaced.
Two good sources of info "Nutrient Management in Recirculating Hydroponic Culture" by Bruce Bugbee, "Principles of Nutrient and Water Management for Indoor Agriculture" where Bugbee is a contributor, and this page.
One issue that required that I change my perspective on before it clicked is that there's no reason why a res in which the EC has dropped considerably should considered spent. The goal of providing chemicals, in the form of "nutrients", is to provide a level of chemicals so that those chemicals are in the "sufficiency" range. That's it. More chemicals does not make the plant grow better; it costs the grower more $$ and harms plants. The goal is the sufficiency range and, in reality, plants don't need high levels of nutrients to thrive if the rest of the grow environment is sound.
This is from one of the Bugbee videos. I found it very helpful.
Check out grows where nutrients are in the 2.x range and there's a good chance that such a high level of nutrients is needed because something in the environment is not allowing the plant to survive at lower levels of nutrients
I do not top up the way the OP has recommended. That approach may lead to nutrient issues because the chemicals in nutrient solution are taken up at very different rates. If you keep adding fresh nutrient solution to a res, you will run the risk of plants getting excess of those nutrients that have been depleted. For example, NO3, NH4, P, K, Mn are taken up very quickly, within a matter of hours. If you top off your res with fresh nutes, you're adding more and more of those chemicals even though they're already in the plant.
If you can analyze lead tissue to determine what specific chemicals need to be added, then add those. Lacking that, the most safe approach is to top up with RO ("add backs") until you've replaced 50% of your res volume or if the res is showing signs of pH instability. That instability is an indictor that the nutrient solution is no longer able to buffer the electrical imbalance caused by nutrient exhaustion and the reservoir should be replaced.
Two good sources of info "Nutrient Management in Recirculating Hydroponic Culture" by Bruce Bugbee, "Principles of Nutrient and Water Management for Indoor Agriculture" where Bugbee is a contributor, and this page.
One issue that required that I change my perspective on before it clicked is that there's no reason why a res in which the EC has dropped considerably should considered spent. The goal of providing chemicals, in the form of "nutrients", is to provide a level of chemicals so that those chemicals are in the "sufficiency" range. That's it. More chemicals does not make the plant grow better; it costs the grower more $$ and harms plants. The goal is the sufficiency range and, in reality, plants don't need high levels of nutrients to thrive if the rest of the grow environment is sound.
This is from one of the Bugbee videos. I found it very helpful.
Check out grows where nutrients are in the 2.x range and there's a good chance that such a high level of nutrients is needed because something in the environment is not allowing the plant to survive at lower levels of nutrients
You do full change outs? When i read under current’s instruction manual it says to do 50% change out usually. I dunno which to do cause i am new. Thanks