First time running this setup SeedHo. My pump is 370GPH, it takes about 15 minutes exactly to fill the table to my line on the net pots, and then 20 minutes to drain it once the pump turns off after running 15 min. I could get a faster pump to reduce the flood time but how do I speed up the drain time, I do have my overflow 1/2" pipe on the table which does a good job but once the pump turns off all the solution goes backwards through the pump which seems to take a long time. I know it's possible to add RO and a certain amount of lucas formula back into the reservoir as needed but I was under the impression it's best to switch the reservoir once every 2 weeks or sooner for the better results, however I'm not opposed to trying the add-back method to one of my tables! I'm not sure if I will need any cal-mag yet, the strains I'm running are bomb seeds thc bomb, liberty haze, skunk x keralas, and critical.
GH Flora Series + 4x4 ebb and flow questions
- Thread starter fuzzyl
- Start date
SeedHo
Well-Known Member
the biggest benefit of e/f is the oxygen exchange to the root zone. from what your saying is your roots are in the water 50mins a cycle, which can be a bad thing due to over feeding, or worse root rot. i`m not sure how many cycles your running it could off set some issues but it will cut back on the oxygen exchange in the root zone which kinda negates the whole purpose of e/f.
as for speeding up the drain time you could lower your drain which will change the height on to your pots(not a deal killer) but it will drain faster, and another thing you may benefit from is reducing your total time of the flood. let it fill and let it drain and that's it. my setup which now is a 4x3 my timer is set for 10mins every 4hrs, it fills in about 4mins, the pump entry is flush with the bottom of the table and the drain is set at 1" both are 1/2". when flooding the root zone has water in it for a total of 15mins. to me its all about healthy root growth, you have that the rest of the plant will follow.
you have to look at the water being pumped in as a vacuum pump for changing the oxygen in the root zone, in with the good out with the bad, of course your feeding at the same time but after a cycle your table doesn`t dry out, your root mat stays wet long after the cycle plus the roots are also holding moisture. that means your plants are getting everything they need.
as far as the res change goes its up to you how you do this, the whole change out weekly came from the nutrient manufacturers. when i got my 1st e/b system i was reading all i could on it, and found that a res change was not necessary unless you had major problems. the most notable person that was vocal about it was neville, the reason i took what he said about it as a profound statement was that he said he was doing it when he still owned seni seeds. that meant his livelihood depended on healthy grows in his greenhouses. so it can be a personal preference and not a mandatory action. he actually said he changed it out once a year or so. whether he meant a season or a physical year i don`t know, but myself i have never gone longer than a grow. you are going to have sediment on the bottom of the res but most of it will come from the clay pebbles, with rockwool it wont be near as much, either way it doen`t affect the plants.
the cal mag is not needed for all strains just a few have shown a deficiency when using lucas`s formula for the flora line, so its not a bad thing to have on hand just in case.
i`m just going to post the whole flora lucas formula with the add back calculator.
"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 does not do it ASAP fast like the phosphoric acid."
as for speeding up the drain time you could lower your drain which will change the height on to your pots(not a deal killer) but it will drain faster, and another thing you may benefit from is reducing your total time of the flood. let it fill and let it drain and that's it. my setup which now is a 4x3 my timer is set for 10mins every 4hrs, it fills in about 4mins, the pump entry is flush with the bottom of the table and the drain is set at 1" both are 1/2". when flooding the root zone has water in it for a total of 15mins. to me its all about healthy root growth, you have that the rest of the plant will follow.
you have to look at the water being pumped in as a vacuum pump for changing the oxygen in the root zone, in with the good out with the bad, of course your feeding at the same time but after a cycle your table doesn`t dry out, your root mat stays wet long after the cycle plus the roots are also holding moisture. that means your plants are getting everything they need.
as far as the res change goes its up to you how you do this, the whole change out weekly came from the nutrient manufacturers. when i got my 1st e/b system i was reading all i could on it, and found that a res change was not necessary unless you had major problems. the most notable person that was vocal about it was neville, the reason i took what he said about it as a profound statement was that he said he was doing it when he still owned seni seeds. that meant his livelihood depended on healthy grows in his greenhouses. so it can be a personal preference and not a mandatory action. he actually said he changed it out once a year or so. whether he meant a season or a physical year i don`t know, but myself i have never gone longer than a grow. you are going to have sediment on the bottom of the res but most of it will come from the clay pebbles, with rockwool it wont be near as much, either way it doen`t affect the plants.
the cal mag is not needed for all strains just a few have shown a deficiency when using lucas`s formula for the flora line, so its not a bad thing to have on hand just in case.
i`m just going to post the whole flora lucas formula with the add back calculator.
"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 does not do it ASAP fast like the phosphoric acid."
SeedHo
Well-Known Member
you can take that formula and make it work with any nutes. you could get the numbers from your new nutes and use his basic layout to make it work. i want say lucas and his partner were great at what they did, but i can say the did a lot of the math for growers. they still have their nute calculator up some where, its just a google search a way.
SeedHo
Well-Known Member
if you mean with the add back, i would use the recommended of week nine of gh`s feed chart, its almost the same as the lucas, so for every 8mils of micro use 5 mils of koolbloom. can you see how it correlates. it will add 350ppm at that dose, it should be a problem. i`ve run the the flora using both the lucas formula for the base ingredients and gh`s recommended for the additives. this way on my add backs i could use the same method.