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Ditching soil - first (DIY) hydro setup

Welcome to the Farm! Plants look awesome! A couple of observations and tips: You didn't say where you are. Are you using the EU 700 scale or the US 500 scale? EC/PPM conversion for different meter types: 1 mS/cm (EC 1.0 or CF 10) = 500 ppm (US scale) 1...
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Ditching soil - first (DIY) hydro setup

by juliando · Started
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Welcome to the Farm! Plants look awesome! A couple of observations and tips:


You didn't say where you are. Are you using the EU 700 scale or the US 500 scale?

EC/PPM conversion for different meter types:
  • 1 mS/cm (EC 1.0 or CF 10) = 500 ppm (US scale)
  • 1 mS/cm (EC 1.0 or CF 10) = 640 ppm (European scale)
  • 1 mS/cm (EC 1.0 or CF 10) = 700 ppm (Australian scale)
I shoot for 1200–1400 ppm on the US 500 scale. I don't start seeing burnt tips until I get over 1600–1800 ppm (US scale).

The brown edges are more likely Mg issues. Nutrient burn usually starts at the tips of new growth, while burnt edges on old growth = Mg issues. (Mg is a mobile nutrient; the plant will rob it from older leaves to support new growth.)

I haven't seen you post any pH numbers; let it drift from 5.8–6.2 in veg and 5.9–6.3 in bloom.

I recommend a complete water change once every 7–10 days. (In rockwool, I flush for 1 hour with plain pH'ed water every 7 days.)

There is not much benefit to "living right on the edge of maximum concentration" if you're not running CO₂, in my opinion—especially if you're brand new to hydro.

If you ever decide to switch nutrients, I recommend Greenleaf MegaCrop (1-part) with supplements to everyone. It's dry (you're not paying for H₂O), it's simple to use, it's very economical, and it produces superior results.


Good luck with your grow! 🌱👊🐙✌️
Thanks for the tips.

I was actually wondering about water changes today after I posted this. I havent done anything significant since they started. But everything looks and smells good so I figured it was OK.

2 of these are growing in a synthetic sponge and 1 in rockwool (I think the sponge actually does better)

ph stable around 5.5 (5.1 - 5.8) with ph up/down - no major swings yet.

I just have the Vivosun ph and ec pen meters - typically i do shoot for that 1450 mark - but thats where im seeing the swings because of the small resevoirs and rapid water loss (bringing me up to 1600 or more if Im not checking every day and topping off)

And that EC number doesnt really tell the whole story right? Just basic concentrations, not specific levels.

I can definitely boost the cal/mag a bit, I add about 5ml 'bush doctor' with my feeds. Good info about the tip vs edge burn.

Thanks
 
If you make the nutes good you dont have to do water changes.but if you make a mistake water change is an easy restart.
 
Once a week I rinse my roots with just PH water, I usually let it go fer 3-4 hrs then refill with fresh nutrients. Looking good though.
I LOVE me some hydro.
Tried soil once indoor, got 3oz instead of my normal 12-14ozs. That's when I decided to just stay in my lane
 
Once a week I rinse my roots with just PH water, I usually let it go fer 3-4 hrs then refill with fresh nutrients. Looking good though.
I LOVE me some hydro.
Tried soil once indoor, got 3oz instead of my normal 12-14ozs. That's when I decided to just stay in my lane
Two tents DWC, then my Larry Suit Lerry freak of the crop.
 

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I loved growing DWC, always felt it was the way!! Looking great, look forward to seeing how this finishes!✊🏼
 
Thanks for the tips.

I was actually wondering about water changes today after I posted this. I havent done anything significant since they started. But everything looks and smells good so I figured it was OK.

2 of these are growing in a synthetic sponge and 1 in rockwool (I think the sponge actually does better)

ph stable around 5.5 (5.1 - 5.8) with ph up/down - no major swings yet.

I just have the Vivosun ph and ec pen meters - typically i do shoot for that 1450 mark - but thats where im seeing the swings because of the small resevoirs and rapid water loss (bringing me up to 1600 or more if Im not checking every day and topping off)

And that EC number doesnt really tell the whole story right? Just basic concentrations, not specific levels.

I can definitely boost the cal/mag a bit, I add about 5ml 'bush doctor' with my feeds. Good info about the tip vs edge burn.

Thanks
5.1-5.8 is way too low of a range, 5.5 is rock bottom in pure hydro. I'd advise keeping your pH range at 5.8-6.2. Mg is less available at lower pH which could be the cause of your Mg problems. Another problem with low ph is Fe toxicity if it dips below 5.5pH

I'd also lower the nutes to 1200ppm, that way when it drains and spikes, It'll only be spiking to 1400-1450.

When it/they gets big, it's going to need to be topped up prolly twice per day

Most hydro setups need to be checked and topped up, at least once per day. Last grow my 4x8 tent was using 15-17 gallons per day and I only had a 20 gal reservoir.

With a 30 gal reservoir; I could have set it to be able to take 3 nights and 2 whole days off... ie Top it up right at lights out Thur. That gives you Thur night, friday lights on Fri night,Sat lights on, Sat night; but you absolutely have to be back and reset it before Sun morning lights on. (I was always too much of a worry-wart and sissy to take off without a babysitter). Knowing that it's going to end up with low water, just mix that batch weaker, so it doesn't spike too high.

EC - Right. It only measures the total electrically conductive salts & minerals. The claim is that ec is a better representation of what's in the solution than ppm. Most people in Europe and Aussie use the 700 scale ec. Personally, I've always used US 500 scale ppm. (you never said what country or state your from)
If you make the nutes good you dont have to do water changes.but if you make a mistake water change is an easy restart.
I always advise regular flushes as preventive medicine to ward off problems b4 they start. It prevents algae blooms, nute deficiencies and excesses, molds, bacteria and a host of other shit. I look at it like cheap insurance.... You don't need it until you do; and then you're glad you have it. 💪 🐙✌️
 

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5.1-5.8 is way too low of a range, 5.5 is rock bottom in pure hydro. I'd advise keeping your pH range at 5.8-6.2. Mg is less available at lower pH which could be the cause of your Mg problems. Another problem with low ph is Fe toxicity if it dips below 5.5pH

I'd also lower the nutes to 1200ppm, that way when it drains and spikes, It'll only be spiking to 1400-1450.

When it/they gets big, it's going to need to be topped up prolly twice per day

Most hydro setups need to be checked and topped up, at least once per day. Last grow my 4x8 tent was using 15-17 gallons per day and I only had a 20 gal reservoir.

With a 30 gal reservoir; I could have set it to be able to take 3 nights and 2 whole days off... ie Top it up right at lights out Thur. That gives you Thur night, friday lights on Fri night,Sat lights on, Sat night; but you absolutely have to be back and reset it before Sun morning lights on. (I was always too much of a worry-wart and sissy to take off without a babysitter). Knowing that it's going to end up with low water, just mix that batch weaker, so it doesn't spike too high.

EC - Right. It only measures the total electrically conductive salts & minerals. The claim is that ec is a better representation of what's in the solution than ppm. Most people in Europe and Aussie use the 700 scale ec. Personally, I've always used US 500 scale ppm. (you never said what country or state your from)

I always advise regular flushes as preventive medicine to ward off problems b4 they start. It prevents algae blooms, nute deficiencies and excesses, molds, bacteria and a host of other shit. I look at it like cheap insurance.... You don't need it until you do; and then you're glad you have it. 💪 🐙✌️
I Guess if your nute is cheap and volume is small and you dont care that your pumping the nature with all those unused nutes you can do a res change for no reason. I usually stick to changing it for fuckups i managed a few grows with 0-1 water change just refils.as for algea bacteria and other stuff clorine or trichoderma work wonders
 
I Guess if your nute is cheap and volume is small and you dont care that your pumping the nature with all those unused nutes you can do a res change for no reason. I usually stick to changing it for fuckups i managed a few grows with 0-1 water change just refils.as for algea bacteria and other stuff clorine or trichoderma work wonders
Point taken. But your argument is weak at best Mr Haze. There is nothing "eco friendly" about growing cannabis indoors, and not much is cheap about it. Period. And unless maybe you're planting it on a riverbank to prevent erosion, or growing it wild; there's not many eco friendly ways to grow it outside either.


How long did it take you to learn how to grow with 0-1 water change? I'm not here to pick and choose which environmental gods I'm going to please or disappoint today... I'm here to help someone new to hydro have every chance at success, so they don't get frustrated and give up on it.

I have a septic tank which I do not put nutes into, instead they go to my trees and lawn and garden. People over here in the US towns and cities have "sewage treatment" plants that treat sewage prior to release back to the environment.

At the end of the day, you have to choose your battles, you can't fight them all 👊 🐙✌️
 
Welp, woke up this morning to some droopy plants in the flower tent.
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So figured Id stop debating the water change and just do it.
Did about 1/3, Brought the ph up a little to 5.8 and the ec down to 1350. I doubled my cal/mag dose to 10ml and added 5ml grow to 25mls bloom.

This is what came out - didnt look/smell bad or anything.
Thanks for the tips everyone, Hopefully this helps.
20251003 110215

*Edit - the dog hair was in the bucket already, didnt come from the system, lol.
 
Point taken. But your argument is weak at best Mr Haze. There is nothing "eco friendly" about growing cannabis indoors, and not much is cheap about it. Period. And unless maybe you're planting it on a riverbank to prevent erosion, or growing it wild; there's not many eco friendly ways to grow it outside either.


How long did it take you to learn how to grow with 0-1 water change? I'm not here to pick and choose which environmental gods I'm going to please or disappoint today... I'm here to help someone new to hydro have every chance at success, so they don't get frustrated and give up on it.

I have a septic tank which I do not put nutes into, instead they go to my trees and lawn and garden. People over here in the US towns and cities have "sewage treatment" plants that treat sewage prior to release back to the environment.

At the end of the day, you have to choose your battles, you can't fight them all 👊 🐙✌️

O i agree with you.i just dont want the kid thinking its not a possability
 
Update - A tale of 2 tents.

While still mostly a mystery due to my current inability to test for anything specific, the flower tent has continued to crash - and just as mysteriously my Veg tent has continued to thrive.

As far as I know - Ive treated them moslty the same (in terms of ph targets and ec levels - the 2 things I can test) aside from changing over to 3/4 bloom fertilizers for the flower tent (a transition that ive also made now for the plant that is doing well)

I hadnt been doing water changes on either system (although i do see the benefits now)
And I had Ec fluctuations and small ph swings - but both systems experienced the same mild swings from normal water loss.

But the results are very different.

6 weeks - just did (yesterday and today) total 60% water change and cut the lights to 12/12
2/3 bloom 1/3 grow - like
8mls cal/mag. ph 6.0 ec 1300
Sittin on her own airstone, lovin life.
20251007 121806


I can think of some differences in the systems -
The flower tent has 2 plants in it.
Theres only 1 air stone between them.
They were 1 month ahead (flowering) and suffered greater damage from the low cal/mag? (Ive since increased)

Lookin pretty sad - ive done some water changes but continue to lose growth. Ph 6.0 ec 1350
Think theyll bounce back? Im ready to scrap them...unless there are any objections?

20251007 121827


And - physically it sucks to work with, needs to be redesigned (to make water changes easier) Its waterproof, got good flow and air inside - Ill just have to make a new interior rack and cover.
 
Why didn't you stick with a prooven DIY Hydrodesign from the Internet? Get rid of that stupid Cardboard................they make plastic these days.
 
Here , If you promise to build your self a good DIY Hydrosystem, I'll give you , only you the key to success. You have to promise and don't tell anyone. ( Stupid European Humor....lol)

Build a Ebb and Flow System . U will have less problems or no problems at all with root rot.

look at the Picture.......that should help you in the future to figure out what is going on and what are your plants doing . Not very helpfull with that grow right now, but for the next one.
You will need a good PPM/TDS and PH Tester. Spend one time money on a Bluelab and your are good for multiple years. And don't forget to calbrate the Ph Tester about every 4 weeks. I've seen people using it, without recalibration. It's easy to see on the Blue Labs. There is a checkmark , when it's gone you have to Recalibrate.
Google fertigation in Coco , even if you don't use coco......you can learn some stuff about how much PPM to feed.
Ph chart2
 
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Do you have air stones in those reservoirs? I think you are just moments from the same issues in the veg tent too. Flowering is a huge amount of stress on the plant and its nutrient needs change. Its likely the reason that the deficiencies/issues are occurring more obviously.
 
Do you have air stones in those reservoirs? I think you are just moments from the same issues in the veg tent too. Flowering is a huge amount of stress on the plant and its nutrient needs change. Its likely the reason that the deficiencies/issues are occurring more obviously.
I do - the plant thats doing well has its own stone, right underneath it. The other resevoir has 1 stone between the 2 plants.
 
I do - the plant thats doing well has its own stone, right underneath it. The other resevoir has 1 stone between the 2 plants.
Dissolved oxygen is very important in hydroponics. Need it for efficient nutrient intake and to keep roots healthy.

I am currently working with a very good comparison for nutrient efficiency due to high dissolved oxygen. Closet grow has a 950GPH air pump for a single reservoir with 4 plants. Tent grow has about 87GPH going into a reservoir with 1 plant. Closet reservoir is getting over 10x more air, but has about 4x more water. So the closet is getting roughly 2.5x more dissolved oxygen per gallon. Closet grow EC never got above 1.5 and the plants loved 1.2 more than anything. Tent grow is about 5 weeks from seed, currently at 1.0 EC, and still hungry for more. With the low airflow I expect to push it to 2.0 EC or so.
 
I do - the plant thats doing well has its own stone, right underneath it. The other resevoir has 1 stone between the 2 plants.
I’d definitely get some more air going. Roots love air stones, they almost begin to encapsulate the stone. Also be sure there is no light leaks into the reservoir. I saw one of your pics has green tinted water, no bueno. I also swore by this stuff for my reservoir, keep it clean……
 
Doesn't look like you need any advise. I should have ask before giving the secrets away.......that realy pisses me off🤬. .......u know, a small TY would have been fine.
 
Forgot to post yesterday - But...
Little bounce back on the larger system. Theyve perked up and are still trying to flower - thought they were a lost cause a few days ago.

But after correcting the issues (low calmag or low uptake due to ph) with some water changes and removing some dead material, theyre lookin better.

Week 9
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The "little" strawberry cough is still doing the best. First full week of flower, not much stretch yet - but the other one took 2 weeks to spread out. Some minor burns, but learning my lessons from the other 2 plants.
Fingers crossed I can keep everything in check for another 8 weeks.

Week 7
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