I have a 18 Gal res, holding 14 gal to the bottom of the net pots 4 2 week old seedlings, veging under 4x45w cfls (5700k) and a 250w hps, 2600 cc air pump with 2 large air stones, also it is DWC and I am using Fox farm nutes. 3 questions- 1) can I use vinagar to lower ph in hydro??? and 2) do I need to change the water after the 1st 2weeks ??? 3) will an 18 gal res get me through flower with 2 plants? (I am assuming 2 will be boys) 2)how do I know if the water needs to be changed, color, odor?? I am not new to growing just to hydro thank you for the help.
Water change how often???
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Al B. Fuct
once had a dog named
No. Vinegar is a product of fermentation and will cause some really evil lookin' cloudy gack in your rez; lemon juice will do the same unless pasteurised.
pHDown is just about the cheapest solution in a hydro shop. If you spend more than about $15 for a 500ml bottle (usually lots less), shop elsewhere. Comes in 2 flavours, one for vegging (nitric acid based, breaks down to nitrogen, plants are OK with that) and another for flowering (based on phosphoric acid, plants like the mild P boost in flowering). This stuff is used in very small quantities; I put 25ml in 125L each time I mix new tanks. A 2L bottle of pHDown lasts me for months.
A lot of nutrient makers recommend a 2-week tank dump interval. Top with water only between dumps- don't add more nutes.
An 18 gal res would easily support 15-20 dependent on size. You'd be topping the tanks every 2 days or so.
Do it by the calendar. I dump tanks every 15 days and add 50%, horticultural grade H2O2 at 1ml per litre of tank volume every 3-4 days to prevent pathogen growth. Don't use H2O2 with organic nutes. Tank water should never have a scent or colour. If it does, there's problems!
midgradeindasouth
Well-Known Member
cool info on hydro AL..
pandabear
Well-Known Member
so you shouldnt add nutes when you top how come?
I have been just monitoring the ppm a but topping up tank with nutes. can you elaborte benifits/negatives to this
Al B. Fuct
once had a dog named
The ratios of N
:K (and other stuff) in a nutrient are tailored to certain phases of growth, whether for veg or flower. During the life of a tank of sauce, the plant will eat those elemental nutes depending upon where it is in the flowering cycle, etc. Say the plant eats half the N, 1/3 of the P and 1/4 of the K in a solution. Then you top up with more nutes, to the specified ppm. What's the resulting ratio of N
:K after you top up? You won't know- your nute meter only measures total dissolved salts. It can't tell you when you have enough of each nutrient and in what ratio they are to the others. If the maker is specifying a 2-week dump interval, they have engineered the chemistry so there is sufficient quantity of each nutrient AND they are in the proper proportion to one another for the life of that batch of sauce. It's safer to not fool around with adding nutes between dumps.
Trying to jockey the ppm so it is the same every day invites fert burns. It's a lot easier to fix a nutrient deficiency (which are HIGHLY unlikely with most commercial hydroponic nutrients) than resurrect a badly fert-burned plant.
Al B. Fuct
once had a dog named
Seems a good time to mention some first principles of growing.
New growers have a great tendency to kill plants with kindness. Overwatering is noob problem #1 followed closely by fert burn.
One thing noobs need to get their heads around is that plants are not V8 engines. They don't work better with more of everything. There's a bell-curve to this; there's too little, just right and dead.
Yes, it's wise to keep an eye on what's going on in the op. However, one should resist the urge to fiddle around with things. If your daily check takes longer than about 5 mins, you could be a chronic fiddler.
New growers have a great tendency to kill plants with kindness. Overwatering is noob problem #1 followed closely by fert burn.
One thing noobs need to get their heads around is that plants are not V8 engines. They don't work better with more of everything. There's a bell-curve to this; there's too little, just right and dead.
Yes, it's wise to keep an eye on what's going on in the op. However, one should resist the urge to fiddle around with things. If your daily check takes longer than about 5 mins, you could be a chronic fiddler.
Al B. Fuct
once had a dog named
hoss, Rosey, thanks for the compliments. 
I suppose if you're making your own hydro nutes, you can get away with competently adding N, P or K individually. However, if you only have the option of adding all at once in proportions you can't control, it's best to follow the maker's instructions.
I have yet to find a nute maker which recommends adding small doses of nutes in between dumps- but you know as soon as I say that, someone will produce a particular nute maker's instruction guide saying to do just that.
I suppose if you're making your own hydro nutes, you can get away with competently adding N, P or K individually. However, if you only have the option of adding all at once in proportions you can't control, it's best to follow the maker's instructions.
I have yet to find a nute maker which recommends adding small doses of nutes in between dumps- but you know as soon as I say that, someone will produce a particular nute maker's instruction guide saying to do just that.
Al B. Fuct
once had a dog named
While it occurs to me, it's possible to perfectly match a tank to a grow op so that the ppm stays the same as water level drops. Don't ask me to tell you how to do it for your op, though. I arrived on the optimal tank volume for my op rather accidentally.
I've recently rebuilt my op with 125L tanks for each of my 820mm square flood trays, each which hold 23 plants. It previously had 100L tanks. These days, with the bigger tanks, ppm stays constant all the way to the minimum water level, which is whatever it takes to fill the flood tray to the overflow and still keep the pump submerged.
With the smaller tanks, as water level dropped, the ppm would rise slightly each day. I mix for 1400ppm; by day 4-5, the tanks would bump up as high as ~1500-1600ppm with about 70% of tank volume remaining. Adding water of course dropped the ppm back to 1400. However, filling the tank to the top would yield often as low as 900ppm, the difference between 1400 and 900 being what the plants had eaten. In this case, the plants were using a certain percentage of the water faster than the percentage of the nutes. I stop adding water when the meter says ~1100ppm.
The larger tanks stay right on 1400 as water level drops. The volume of water is apparently better matched to the nutrient consumption rate. If I refill with water, the ppm will drop, by a somewhat lesser amount than with the smaller tanks.
I'm happier with the consistent 1400 and am learning to live with looking at a half-empty tank- if there's enough to keep the pump submerged on flood, all is well. I'm resisting the urge to top tanks for the entire 2 weeks if possible. If air temps are warm, evaporation increases, forcing me to add some water, but I don't totally refill the tanks.
I've recently rebuilt my op with 125L tanks for each of my 820mm square flood trays, each which hold 23 plants. It previously had 100L tanks. These days, with the bigger tanks, ppm stays constant all the way to the minimum water level, which is whatever it takes to fill the flood tray to the overflow and still keep the pump submerged.
With the smaller tanks, as water level dropped, the ppm would rise slightly each day. I mix for 1400ppm; by day 4-5, the tanks would bump up as high as ~1500-1600ppm with about 70% of tank volume remaining. Adding water of course dropped the ppm back to 1400. However, filling the tank to the top would yield often as low as 900ppm, the difference between 1400 and 900 being what the plants had eaten. In this case, the plants were using a certain percentage of the water faster than the percentage of the nutes. I stop adding water when the meter says ~1100ppm.
The larger tanks stay right on 1400 as water level drops. The volume of water is apparently better matched to the nutrient consumption rate. If I refill with water, the ppm will drop, by a somewhat lesser amount than with the smaller tanks.
I'm happier with the consistent 1400 and am learning to live with looking at a half-empty tank- if there's enough to keep the pump submerged on flood, all is well. I'm resisting the urge to top tanks for the entire 2 weeks if possible. If air temps are warm, evaporation increases, forcing me to add some water, but I don't totally refill the tanks.
Al B. Fuct
once had a dog named
We'll be here!
Roseman
Elite Rolling Society
last year, at my first Hydroponic grow, I was faced with the same dilima. It ws time to add a gallon of water, (top it off) , they (6 plants) were drinking a gallon a day. I knew precisely how much to add to 6 gallons when it was DRAIN and RE-plinish time, but I wasn't sure aobut topping it off. Several times I tried measuring 1/6 nutes and adding them to the one gallon of water, and I got mild nute burn every time. I learned thru experience to top off with pure water daily and replinish every 7 days. I also learned that everytime I drained and replinish, I got a growth spurt. I aasked my mentor and he said it was the Oxygen bath to the roots,t aht they loved to take a brief 5 or ten minute breather from the DWC or deep water. I even learned I could speed up growth by draining and adding back the same water just to give the roots a air break. The more air stones I added, the faster growth I got too..
Al B. Fuct
once had a dog named
Of course there is! You DO need to know what the total dissolved salts in your nute solution may be. TDS/EC/PPM is a good guide to nutrient strength. You just don't have a usual need to know how much individual nutrients are in a solution- if you mix and dump per the nute mfr's instructions. However, if you have a burning need to find out how much N is in your solution, you can go drop about $20-30K on a mass spectrometer.
Al B. Fuct
once had a dog named
Not surprising, Rosey. That mirrors most people's experiences from topping up in mid-tank life.
7 days is a fairly short dump interval- unless you have a very small reservoir, as you might have in bubbleponic systems. The smaller the tank, the more likely you are to see the ppm jump up as the water is used faster than the nutes.
Just draining and refilling will oxygenate even your 'old' water. Doesn't actually take too much splashing about to dissolve O2 in water. Yep, oxygen to the roots is one of the big growth speed factors, as you have discovered.
Now... if we could only get you to splash out on a 400W HPS, Rosey!
You do get great results from your CFLs, but you would be ASTONISHED with wot you'd get out of a good sized HPS for your space (and good ventilation).
hossfield
Well-Known Member
20-30k eh, hmmm seems like a good investment, itd pay for itself in about a thousand years, hey roseman were u in a bubbler? cause im setting up a aero, have a water pump and misters and everythin, think gettin a digital timer and havin it run 1 min on 1 min off would help? or should i just let it go 24/7
Roseman
Elite Rolling Society
Al B Says:
Now... if we could only get you to splash out on a 400W HPS, Rosey! You do get great results from your CFLs, but you would be ASTONISHED with wot you'd get out of a good sized HPS for your space (and good ventilation).
Roseman replies:
You are right as usual, Al B. You are right. I admit it and I agree.
I started out with CFLs for one reason, STEALTH! I needed it and it made sense and I was timid about growing and getting started. AND after I got two 85 watt bulbs, and started researching, I made up my mind to be hard- headed and stubborn and go with CFLs and also I wanted to pull for the underdog, and encourage the Newbies to go for it, and grow. ( I preach a lot that at the end of our lives, we only regret what we did not try or do.) So I wanted to encourage the young, timid, inexperienced low income or low budget dude to go for it and try CFLs.
I admit I had to put three bulbs on one bud to get it to a coke bottle size and tight and full. I had to grow for 4 months to get what others get much sooner with HPS, and I wanted a CROP, a BIG Harvest, not just a oz or two oz of buds. I moved those bulbs twice a day and finished with 5 85 watts and 2 42 watts on one plant. But look at what I got laying on the kitchen table!
I want the HPS, but then I 'd need a cooler or airconditioner, and a bigger fan and some kind of ventilation system.
AND so I stand by the fact that if the grower is new, wanting to grow for personal use, and has a limited budget, and has very limited space like 3 by 3 foot 4 feet tall, and wants to do the SEA OF GREEN , is on a low income and not make a lot of heat, not use a lot of power, be knowlegable about how close to put the lights, and needs to be able to easily move the lights around as the plants grow, and has the need and desire for STEALTH, then the Spiral CFLS, and Bubbleponic System will be PERFECT !
Now... if we could only get you to splash out on a 400W HPS, Rosey!
You do get great results from your CFLs, but you would be ASTONISHED with wot you'd get out of a good sized HPS for your space (and good ventilation).Roseman replies:
You are right as usual, Al B. You are right. I admit it and I agree.
I started out with CFLs for one reason, STEALTH! I needed it and it made sense and I was timid about growing and getting started. AND after I got two 85 watt bulbs, and started researching, I made up my mind to be hard- headed and stubborn and go with CFLs and also I wanted to pull for the underdog, and encourage the Newbies to go for it, and grow. ( I preach a lot that at the end of our lives, we only regret what we did not try or do.) So I wanted to encourage the young, timid, inexperienced low income or low budget dude to go for it and try CFLs.
I admit I had to put three bulbs on one bud to get it to a coke bottle size and tight and full. I had to grow for 4 months to get what others get much sooner with HPS, and I wanted a CROP, a BIG Harvest, not just a oz or two oz of buds. I moved those bulbs twice a day and finished with 5 85 watts and 2 42 watts on one plant. But look at what I got laying on the kitchen table!
I want the HPS, but then I 'd need a cooler or airconditioner, and a bigger fan and some kind of ventilation system.
AND so I stand by the fact that if the grower is new, wanting to grow for personal use, and has a limited budget, and has very limited space like 3 by 3 foot 4 feet tall, and wants to do the SEA OF GREEN , is on a low income and not make a lot of heat, not use a lot of power, be knowlegable about how close to put the lights, and needs to be able to easily move the lights around as the plants grow, and has the need and desire for STEALTH, then the Spiral CFLS, and Bubbleponic System will be PERFECT !
Roseman
Elite Rolling Society
I use a modified DWC system, with added irragation bubbled to the root base in tubes.
I would highly suggest an extra air stone in the tank, I'd run 24/7 and I 'd try to get a cheap submersive pump and pump in a tube the bubbly air=oxygen enriched water to the root base for a FAST Healthy Grow. The $5.00 timer at Lowes or home depot works great.