pH control in reservoirs?

[ChemPro]

This is my first attempt at a flood drain system. Yesterday I mixed my nutrients and adjusted my pH to 5.9. But today I am at 7.0.

I'm using the 3 part flora series by general hydroponics at half strength which has always worked well in my DWC. And I use pH down to correct the pH. But a full +1 difference over a day is a concern.

Is it normal to have to correct pH in a reservoir every day?

Facts: using clay pellet as the medium. I washed them and soaked them overnight. However, I didn't adjust the pH of the water I soaked them in so that may be the issue.

Also, I don't have a water filter so I am using tap water.

In addition to the pump that is flooding my table I have another pump in my reservoir to circulate the water.

Any advise?

 

[horribleherk]

do you have any light hitting your reservoir? I recently switched from e&f to a waterfarm & my ph. issues are gone I also use tap water & gh 3 part nutes even when I had my reservoir covered good in e&f every few days ph adjust was a must I'm starting to like the dwc/ waterfarm

 

[ChemPro]

do you have any light hitting your reservoir? I recently switched from e&f to a waterfarm & my ph. issues are gone I also use tap water & gh 3 part nutes even when I had my reservoir covered good in e&f every few days ph adjust was a must I'm starting to like the dwc/ waterfarm

Its covered good. The small area I have open to allow me to prode is covered by panda film with the white side facing up, It took 75mL of pH down to bring it down to 6.1 (37.5 gallons)

 

[horribleherk]

I've got a friend doing an 4x8 e& f hydroton in baskets & loose hydroton covering the rest of the tub he now covers the tub in panda film with holes for the plants I'm don't know how many times he floods in a day but when the plants were small the nutes were exposed to light every flooding but out of rockwool & coco in smart pots the hydroton is doing the best for him in spite of continuous need to adjust

 

[ThaMagnificent]

It's the tap. I was having the same issues. My water is low ppm but the ph would always rise because of the high alkalidity of the tap water.

 

[Douglas.Curtis]

When you switch from tap water to R/O (besides getting a cleaner end product), give this thread a look. Since you're in a roots-out system you'll be shooting for 5.5'ish pH to start with.

R/O makes pH changes super predictable.

 

[ChemPro]

Just bought this. Hope it was worth the $200. I'll probably have to start adding calmag right? Any other things I need to worry about running RO water?

 

[Douglas.Curtis]

Just bought this. Hope it was worth the $200. I'll probably have to start adding calmag right? Any other things I need to worry about running RO water?

No need to 'have' to use cal-mag, unless your nutrient mix is off and requires it.
I've used r/o for 15 years and haven't needed any cal-mag, ever.

• R/O has significantly fewer hassles than tap-water is capable of creating.
• It's the same every time
• It has all the junk cleaned out of it
• pH changes are stable and predictable
• plants love it
• when you move, you won't have to re-learn how to grow with your new water supply

There are ZERO downsides to using r/o over tap, except the added cost. Considering the differences in quality? It's a super cheap price to pay.
(edit: Yes, that filter will work, as long as your water pressure is at least 40psi. I use one of those for my 1000w dwc garden and veg room)

 

[ChemPro]

No need to 'have' to use cal-mag, unless your nutrient mix is off and requires it.
I've used r/o for 15 years and haven't needed any cal-mag, ever.

• R/O has significantly fewer hassles than tap-water is capable of creating.
• It's the same every time
• It has all the junk cleaned out of it
• pH changes are stable and predictable
• plants love it
• when you move, you won't have to re-learn how to grow with your new water supply

There are ZERO downsides to using r/o over tap, except the added cost. Considering the differences in quality? It's a super cheap price to pay.
(edit: Yes, that filter will work, as long as your water pressure is at least 40psi. I use one of those for my 1000w dwc garden and veg room)

Right on man. Thus far my pH has remained constant. Though I am a little concerned that I'm not getting as much growth from my flood table as I have in DWC and coco. Is slower vegetative growth typical in flood drain systems?

 

[ruwtz]

I've just come indoors and from soil to a flood table using tap water. My pH rises daily by around a full stop and takes 50-100ml pH down to get it back to around 5.8.

My tap water has low alkalinity (soft) but is highly alkaline (pH7. 8 ) - they are not the same thing.

I ran in soil for years with tap no problems but I'm learning hydro is different/more sensitive. A downside to RO that hasn't been mentioned is inefficiency: something like 3 gallons waste to produce 1 gallon RO. I'm looking into it but this is very unappealing to me.

Most ferts will buffer pH but I have been warned that some products will swing pH - I'm using Rhizoblast and this has been mentioned.

 

[ruwtz]

Also I recently added a hydroton layer to float my Pargro blocks; this was washed and rinsed but there is still a clay residue on my table after flooding. I've not tested but this could throw pH also, not to mention adding undesirables back into the res when draining.

 

[Douglas.Curtis]

I have relatively little experience with tap-water, it has different elements in it, depending on where you live and they affect pH. The Stealth RO series of filters have inserts you can put in the 'waste' line, changing it to a 1:2 or 1:1 ratio. With your soft water you can run 1:1. I'm sure there are similar options for your r/o machine, check around. Look for ways to save and re-use your 'waste' water as it's still clean and great for a lot of things, including lawns and veggie/flower gardens.

My experience is with GH nutes and all their nutrient lines are buffered well. I would see how the swing is with straight r/o, get a good idea of what the nutes you're using are doing on their own. Additives with pH changing properties need to be used carefully as well, to work with the pH swing.

F&D depends largely on the root zone temps and airflow, making sure you have full drainage makes a difference as well. You need at least 72F in the root zone for 'medium' based grows. The warm medium speeds evaporation, creating a nice humid area which grows fuzzy roots. Without airflow and warmth, very much slower.

Fun, yeah?

 

[ChemPro]

I have relatively little experience with tap-water, it has different elements in it, depending on where you live and they affect pH. The Stealth RO series of filters have inserts you can put in the 'waste' line, changing it to a 1:2 or 1:1 ratio. With your soft water you can run 1:1. I'm sure there are similar options for your r/o machine, check around. Look for ways to save and re-use your 'waste' water as it's still clean and great for a lot of things, including lawns and veggie/flower gardens.

My experience is with GH nutes and all their nutrient lines are buffered well. I would see how the swing is with straight r/o, get a good idea of what the nutes you're using are doing on their own. Additives with pH changing properties need to be used carefully as well, to work with the pH swing.

F&D depends largely on the root zone temps and airflow, making sure you have full drainage makes a difference as well. You need at least 72F in the root zone for 'medium' based grows. The warm medium speeds evaporation, creating a nice humid area which grows fuzzy roots. Without airflow and warmth, very much slower.

Fun, yeah?

My water temps are around 65F to 69F. All in all I like the low maintenance. I have 2 options with my stealth RO filer. 1:2 and 1:1. I am running 1:2 because it's stated in the manual that I will get a longer life out of my filter using a higher waste setting. Running it for less than a full day gives me enough water for a week and that includes my 55 gallon flood table reservoir, and 33 coco plants in 2 gallon smart pots. It was a good decision as my pH has not changed since Saturday. Before hand I would adjust nutes and add 100mL of pH down to get my desired pH. With RO water after I add my nutrients my pH falls in range and stays constant without pH down. It was a wise investment. Looking forward to doing an apples to apples comparison on yield effects using RO water.

 

[ruwtz]

Low ppm's is definitely attractive and a great base for our purposes: articulated control over what we feed plants is highly attractive. I am currently considering the switch especially as I am firefighting issues in early veg that tap water may or may not be contributing to, despite acceptable or low ppm levels and low alkalinity as per my city water report. I am not yet convinced that RO solves everything for me at this point, and i've grown lots of things for a long time with the same tap no issues.

The waste is still a hangup for me. At whatever setting that waste water has the contaminants at higher concentrations due to the RO process, AFAIK, so why would I put this on the rest of my garden?? I have seen examples where folks' tap is 250ppm and there waste comes off at 1000ppm. Higher settings and the filter needs replacing more often; the RO membrane alone is not cheap.

Also I have some installation challenges: I have one outdoor faucet that already leaks and the nut is jammed up so I can't remove, and I don't have the room at the faucet for collection reservoirs for RO and waste. I either have to replumb or find another way.

Is it practicable/does anyone put the filter on temporarily for processing, collect what you need then remove and store until next time?

Please know I am very thorough in running through the pro's and cons of any decision, based mostly on this occasion onconsumer research/reviews of the Stealth RO line, so you guys' experience is equally valid in this respect and i'm willing to be convinced yet that the switch is worth the cost, the effort, and the waste.

 

[ChemPro]

Low ppm's is definitely attractive and a great base for our purposes: articulated control over what we feed plants is highly attractive. I am currently considering the switch especially as I am firefighting issues in early veg that tap water may or may not be contributing to, despite acceptable or low ppm levels and low alkalinity as per my city water report. I am not yet convinced that RO solves everything for me at this point, and i've grown lots of things for a long time with the same tap no issues.

The waste is still a hangup for me. At whatever setting that waste water has the contaminants at higher concentrations due to the RO process, AFAIK, so why would I put this on the rest of my garden?? I have seen examples where folks' tap is 250ppm and there waste comes off at 1000ppm. Higher settings and the filter needs replacing more often; the RO membrane alone is not cheap.

Also I have some installation challenges: I have one outdoor faucet that already leaks and the nut is jammed up so I can't remove, and I don't have the room at the faucet for collection reservoirs for RO and waste. I either have to replumb or find another way.

Is it practicable/does anyone put the filter on temporarily for processing, collect what you need then remove and store until next time?

Please know I am very thorough in running through the pro's and cons of any decision, based mostly on this occasion onconsumer research/reviews of the Stealth RO line, so you guys' experience is equally valid in this respect and i'm willing to be convinced yet that the switch is worth the cost, the effort, and the waste.

Yes, I use mine temporarily. I connect the RO filter to the same water supply that supplies my washing machine. If you have a washing machine you will have a hot water feed and a cold water feed. Use the cold water feed, the connection is threaded just like a garden hose and my RO filter has a garden hose attachment. So it takes less than a minute to unhook my washing machine and hook up my RO filter. I then run my waste water stream into my laundry room sink drain.

I wouldn't water your garden with the waste water either which is why I throw it away. I run the clean water to a 55 gallon rubber made tote. I actually have 5 gallon buckets in the 55 gallon tote and when a bucket gets full I remove it and if it overflows it just gets collected in the tote. In about 8 hours I have enough water to change my 55 gallon reservoir once a week and enough water to water my 33 coco plants for a week. Then I unscrew it, hook my washing machine inlet up again, and use my regular water for everything else. The hook up and re hook up takes 1 minute tops. The entire filter weighs 10 pounds so I can put it away and pull it out again pretty easily.

The only pain in the butt is having to be at your house while its running unless you have an overflow mechanism installed to prevent a flood. I end up setting my alarm clock every 2 hours just so I don't forget its running. It would take 4 hours minimum to fill my 55 gallon tote so I do have windows in which I can leave my house, I just make sure I empty the tote before I leave and make sure I am back in less than 4 hours.

As far as wasting water and the cost. The average cost of water according to a google search I just did is $1.5 per 1000 gallons of water. So if I get 1000 gallons of RO water I am putting 2000 gallons of waste water down the drain. Based on the amount of water I use (~4680 gallons a year) I will run 9360 gallons down the drain costing me $14.04 a year. So the cost isn't an issue other than the upfront investment of $200 for the filter and filter changes.

The filter produces water no higher than 25 ppm thus far. I am curious to see what ppm the waste water is at. My tap water is around 350ppm so I had to do something.

 

[ruwtz]

Yes, I use mine temporarily. I connect the RO filter to the same water supply that supplies my washing machine. If you have a washing machine you will have a hot water feed and a cold water feed. Use the cold water feed, the connection is threaded just like a garden hose and my RO filter has a garden hose attachment. So it takes less than a minute to unhook my washing machine and hook up my RO filter. I then run my waste water stream into my laundry room sink drain.

I wouldn't water your garden with the waste water either which is why I throw it away. I run the clean water to a 55 gallon rubber made tote. I actually have 5 gallon buckets in the 55 gallon tote and when a bucket gets full I remove it and if it overflows it just gets collected in the tote. In about 8 hours I have enough water to change my 55 gallon reservoir once a week and enough water to water my 33 coco plants for a week. Then I unscrew it, hook my washing machine inlet up again, and use my regular water for everything else. The hook up and re hook up takes 1 minute tops. The entire filter weighs 10 pounds so I can put it away and pull it out again pretty easily.

The only pain in the butt is having to be at your house while its running unless you have an overflow mechanism installed to prevent a flood. I end up setting my alarm clock every 2 hours just so I don't forget its running. It would take 4 hours minimum to fill my 55 gallon tote so I do have windows in which I can leave my house, I just make sure I empty the tote before I leave and make sure I am back in less than 4 hours.

As far as wasting water and the cost. The average cost of water according to a google search I just did is $1.5 per 1000 gallons of water. So if I get 1000 gallons of RO water I am putting 2000 gallons of waste water down the drain. Based on the amount of water I use (~4680 gallons a year) I will run 9360 gallons down the drain costing me $14.04 a year. So the cost isn't an issue other than the upfront investment of $200 for the filter and filter changes.

The filter produces water no higher than 25 ppm thus far. I am curious to see what ppm the waste water is at. My tap water is around 350ppm so I had to do something.

Interesting, although its worth noting waste isn't just measured in dollars: water is a precious resource and in dry regions water conservation is a hard fact of life.

 

[Douglas.Curtis]

Yes, I use mine temporarily. I connect the RO filter to the same water supply that supplies my washing machine.

Use a $4 garden hose 'splitter' with separate valves. You can leave your washer hooked up, just connect the r/o machine and turn on the valve for it on the splitter.

I wouldn't water your garden with the waste water

I would, perfectly fine for veggies. Unless there's something 'bad' in your water supply? Cannabis takes up elements in additional pathways than passive ionic uptake, veggies generally don't. Using hard water is significantly less of an issue for vegetable gardens and lawns and flower gardens.

The only pain in the butt is having to be at your house while its running unless you have an overflow mechanism installed to prevent a flood.

You're looking for something like this... It's a simple float valve. I have one screwed into the top of a 55gal drum (on the inside). Works a treat. Make sure you test it's installed correctly, I had one flood before adjusting and it's been great and reliable ever since.

The filter produces water no higher than 25 ppm thus far. I am curious to see what ppm the waste water is at. My tap water is around 350ppm so I had to do something.

When mine hits 14ppm it's time for a change. I've heard you can get biological crud when the buildup inside gets too great. I don't have a back-flush to 'clean' it so it's a straight replacement of the filter.

 

[ChemPro]

Interesting, although its worth noting waste isn't just measured in dollars: water is a precious resource and in dry regions water conservation is a hard fact of life.

I agree. In the case of my water the waste goes to the sewer and eventually ends up in my utility's waste water treatment plant where it is cleaned and reused. Of course the carbon footprint of whatever process is used to treat the water is always a concern. But the water itself is still available.

Now I have 2 options.

1. I use tap water at a high ppm. Say 350 ppm. I use 100 gallons of 350 ppm water and turn it into 100 gallons of 1,000 ppm water once I add nutrients. My plant uses the water and evaporates most of it off into the air where it is now 0 ppm water vapor that eventually makes its way back into the environment where it will reach cloud level until temperature drops enough to create rain (clean water, unless acid rain is an issue). I have now used my plant as an indirect water filter and all the ppm are now stored in the plant which will get volatilized into the air when I smoke it. The left over water I have during a reservoir change is around 1000 ppm and that gets dumped down the toilet.

2. I filter my water to create 100 gallons of 0 ppm water and 200 gallons of water with "X" ppm. I don't know if X is higher than 350 necessarily because my filter itself is collecting a lot of junk in it that is not going to the waste water. But if it is less than 350 ppm then I am less concerned as my purification process utilizes pressure and gravity to power it and the only carbon footprint used is the energy needed to make the filter itself. Therefore the water I dump down the drain is cleaner than the water I bring in if X < 350ppm. But then as far as the environment is concerned I've now turned a water issue into a landfill issue when I throw my filter away. If X is higher than 350 ppm I then need to ask myself if X is greater than my typical waste water such as the toilet water, and the water my washing machine uses as well as my soapy shower drain water. I'll know the answer to this soon.

If it is higher I think its still not necessarily a deal breaker. After all, most energy crisis is traced back to carbon emissions. And in the case of using the water to grow plants I'm actually taking carbon dioxide out of the air and converting it into the physical building blocks that make the plant (a less concerning form) and giving off oxygen in the process.

But in a place that is lacking water such as certain areas of Nevada and California I'd be a butt head to waste more on my plants. Kinda like that jerk who waters his lawn during drought season. But as far as ppm is concerned there is a finite amount. Whether you purify it, leave it as is, flush it down the drain or whatever the total amount of solids are always going to be the same, the only difference is where you have those solids go.

 

[ChemPro]

Use a $4 garden hose 'splitter' with separate valves. You can leave your washer hooked up, just connect the r/o machine and turn on the valve for it on the splitter.

Awesome. I will do just that. I actually have another drain in my basement. I have an overflow tube installed near the top of my RO collection tub that will flow into my drain if it starts to overflow.

 

[ChemPro]

Tap water came in at 400ppm, my waste water came in at 490ppm