replacing water in reservoir

i just started hydroponics for the first time. it has been just under a week and i have not yet changed the water in reservoir. i did ph it once to bring levels back down to 5.5 i think this is the right ph?

when changing water in reservoir should all of the water be replaced with new water and nutrients? half and half? only nutrients. what is the scoop on replacing reservoir water and proper ph?

5.5 is a bit low for my liking, i like 5.8. some people top-off between rez change-outs with plain ph'd water, some top-off with some nutes. some folks change out weekly, others every other week.

I agree that 5.5 is too low - I also target 5.8 for my systems. How often do you check your pH? There are tons of opinions on solution changes. I change mine every two weeks, and top off with fresh water and adjust PPM as necessary.

Can you give us some more info? What kind of system are you running? What's your water source? What nutrients are you using? Etc?

I try to keep things between 5.8 and 6.3, I change every week to 10 days. When I do change it out I do change all of it and top off with whatever the mix is that is in the res. I try took keep a gallon jug on hand for this. I do agree with GCVT that there will be lots of opinions about this. Who is right? Who knows? Mine is just one mans opinion, take it for what it's worth

pH sensitivity depends a lot on nutes. I don't worry if mine is between 5.5 and 7. I change the water completely each week and reset nutes according to the nute company's feeding schedule. That's the only way to know you are keeping the right nute concentration. I keep water level steady during the week with plain water.

i use the nute co.'s suggestions as a guide, i never follow it. they're notorious for suggesting inflated strengths so you can use it up and buy more.

Silky Shagsalot said:

i use the nute co.'s suggestions as a guide, i never follow it. they're notorious for suggesting inflated strengths so you can use it up and buy more.

Click to expand...

Ditto....I use botanicare.......their guide will burn your babies to a crisp...unless you have a super heavy feeding strain...

hey, i appreciate everyones help!

a little more about my system. the image below shows a drip system/dwc bubblephonics type setup i made. i had a little bit of room in my 12/12 closet for another plant. i took a bubba kush clone and put her straight 12/12....i thought this would be a good way to experience hydroponics for the first time...two airlines are fed into the resevoir. one acts as a pump for the drip system and the other rests in resevoir to 1. oxygenate water and 2. bottom feed.

i have a bunch of different nutrients. for this plant i think i am going to stick with general hydroponics or possibly supernatural.

this system has only been up for about a week now. i have checked the ph two days ago and had to lower it a bit. plant is still young and is not requiring much nutrients i fed around 400-500 ppm. water source is from aged tap with a base ppm of around 130.

i use humic acid in my coco grow. is this recommended in hydro also?

First off we all recommend a little research before jumping head first into any endeavor one decides to pursue, and much of your questions are simple enough to be answered by a little time spent reading before posting. None the less, we proceed...


I have stuck to whole advanced nutrients line (although quite expensive when changed weekly, but hey to each their own) my whole hydroponics career, applied according to their calculator on the website, and I have only found picky ass, expensive sativas that get too tall for indoors anyways, to not like the ratios they give you (very explicit, and easy to follow by the way). Getting to my point...

I use DWC as well, and change reservoir solutions weekly (recommended by AN) with new distilled water, pH and ppm adjusted of course, and into the res it goes. Never encountered a problem in my time, but give the credit to the additives AN produces (no shock, jump-start, and the mass amount of microbial beneficials they load their products with). This is basically up to you, if you have the money to do it weekly, then do it. Its a sure fire way to not run into problems, and to help support our already shaky Hydroponics market.

Also, pH tends to 'swing' through a range over a period of time, and quite quickly after a new res change because it lacks the needed buffer 'pH down' introduces to the solution, essentially slowing the 'swing' to a creep instead of a jog. I would recommend a pH pen instead of the old school, half a vial, three drops, and shake method. Not going to lie though, I will revert to this method when I am out of calibration solution for my pen, and I think its playing jokes on me. A EC/PPM pen is pretty helpful as it indicates basically the strength/concentration of the nutrients down to the parts per million in the water. Everyone here will tell you a given pH they like to roll with but I bring mine to 5.5 almost every time, let it creep to 6.2, and bring it on down again. The current ladies eat it up, but they will say that the most nutrient uptake occurs at 5.6-5.8. Hence the reason I bring mine to 5.5 so it can swing through that given range, and creep past picking up the smaller nutrients not just the basic NPK high in the pH range. But beware to high of pH for too long will start to cause whats known as a nutrient lock out, when that occurs I flush with distilled (0 ppm 5.0 pH out of the bottle) for 24 hrs, and then reset the res to proper ppm, the following day. Another note about pH, always do it last. Make sure water level is right, then check the ppms, adjust to target number, THEN adjust the pH or you're going have a hard time maintaining.

Another thing, I recommend all this technology to help you grow but honestly the more you get experienced with the plants, and what each different strains like you can basically look at the leaves/plants and they will tell you what/if anything you're doing right. Hydroponics is a very accelerated method of growth, so when one thing crashes (exhaust fan, water pump, air pump, number of things at any time) you can lose a crop with tremendous speed with no chance of recovery no matter how forgiving your strain is claimed to be.


This will have to conclude my stoned, broken sentenced ramble so I hope it helps you with at least one of your questions somewhere down the line haha, until then just keep reading!

Be easy!

-Monstro

thanks for the detailed post. ive been growing in coco and soil for quite some time now. i do have a ph pen which i use after adding nutrients at every water. i also have a ppm reader. plant is taking off already. i have never seen a plant adjust so fast after transplant than with this hydro setup i am using. it was a spare the moment type thing and i was bored. im going to start increasing ppm this water. lay off the veg nutes and go straight flower nutes. what do you think of supernatural nutrients? here are a few of my soil and coco grows.

The fertilizer manfacturers make fertilizers for the vaerage user and the vaergae of strian requirementsin general, with changes like Sensi blend t etc being about the only deviation from mixing for the v average requirements. Different systems opertrate better with different pH's. ie aoero does better at a lower pH than inert hydro which does better at a lower pH than DWC etc. This is related to both the water chemsistry in the resrvoir and due to differing root systems.

There are many reaons one can have for changing nutrients in a chemivcally based system.
* To remove oganics from normal root death
* To keep the nutrients ionically balanced (pH)
* To keep the differing fertlizers in proper ratios with each other
* To maintain practical calcium and carbonate concentrations
* To maintain low levels of bacteria and protozoa
* In order to regulary disinfect and flush the systems with chlorine or Hydrogen Peroxide or even just pH balanced water

*** There are cheaper bandaid methods to deal with theses that are cheaper but not as effective and ae often just guess work at best as few growers keep test equipment and reagents to test for all nutrient levels yet alone know how to individually adjsut them, so it is knowingly have your nutrients out of balance etc or change the nutrients instead. Nutrient manfacturers charge absurdly high costs for their products which cause many people (possibly the majority) to not regularly change out their reservoir nutrient water.

for hydro, a pH of 5.5 is perfect. I try not to let it get below 5.3 or above 5.8...

as for nute changes, yes always drain the old nutes, and replace with fresh nutes.

as for how often, that depends on you and the type of system you have.

I do DWC. in an 18 gallon tote, but filled to 12 gallons with nutrient solution... I don't change my nutes until my plants have drank 12 gallons of fresh water. Since they drink about 1 gallon of water a day, I change them about every 12 days...

Like I said, we all do it a little differently... In time you'll figure out what works best for you. And like some one else said, doing some research and reading will be a great help for your personal growing culture.

-S

I think if I thought the feeding schedule offered by a nute company was too high in order to sell more product, I would not use that product at all. I use Humboldt Master A&B and find the feeding charts on their website to be very reliable. Monstronium above says the same about AN.

right on. i will post new pictures tomorrow plant is loving this hydro!

last i heard advanced had an old calculator, and a new one. i don't know if there is a third by now, but a.n. users had many problems getting it down. you know their old site is back up...

I use the direction on the GH label and it works fine for me as well. I just start at the low end and work my way up...I would rather error on the side of caution.

I believe your original question asked about topping off betwwen res changes and nute/Ph ranges.

1. Top off with plain h20 between changes to maintain an acceptable water level for pumps and plants...no nutes mid-cycle.

Frequency of res changes for most people depends on how many plants are maintained by what size res. The more plants per gallon it has to support the more often you need to change out nutes.

2. Google a ph chart for hydroponically grown cannabis, I believe you will find 5.8 to be the desired level. Nutrient uptake by the plant depends on the acidity/alkilinity of the solution not the other way around. Most nutes have Ph buffers in them to land in a certain range and will drift upward as nutes are consumed and toxins/waste are released by the plants. I check and buffer Ph daily so I never have to make significant changes to it.

I know I appear to be a noobie but you will find this information to be sound.

Hope this helps,
-Saul

yes gh full strength works well. i also work my way up. last grow i had mild nute burn and this time havent had it yet....well maybe once early in veg.