RO Membrane wearing out fast

[Pulsar]

QUOTE=theother;6730840]Didn't have a chance to read it all but I will clarify' I don't think I was clear in the last post. Tds creep is happening because an ro is cycling on and off very regularly. The lamps make the water evap the ATO float goes down and the ro starts making water. Happens often and makes small amounts of water. The tds creep is pumped into the do resin depleting it faster.

Your understanding of what is happening is correct, however, who said anything about DI only being affected? This affects every stage.DI just happens to be the most expensive of the bunch.


Ours is different because we pull out 200 gallons and make 200 gallons. No on and off cycling in most hydro systems I have seen. If you did have a float set up to top off a hydro system as the plants drink it you would get tds creep. We of course will get tds creep while the system is off, and that first 1/2 gallon will have a higher tds than the rest, but it will be diluted by the next 200 gallons of water.

The way youre making water is the better way, for sure, but I assure you, not everybody is doing it this way. There are lots of guys plumbing their units straight into their Reservoirs to replace Evap and water loss from Plant uptake.

That's all I'm saying, the tds creep is caused by small volumes of water frequently coming out of the membrane. Hydro (at least in the sense we are all talking about) doesn't work this way.

I dont recall ever discussing specific methods of Hydro in this discussion. Weve just been discussing RO units and membranes/media. I would disagree with the statement that "Hydro doesnt work this way." It entirely depends on the method of hydro dude. For example, say you make a large batch of water for a large DWC operation. Any expert DWC grower will automate their water level replenishment to avoid too large of a PPM spike when the water level drops. Thats an entire other discussion, but theres not always going to be a symbiotic relationship between salts and water level based on what the plants are using. There are plenty of growers, who for convenience sake, are teeing off a water line from their main, straight into their RO unit, and then plumbing that to a float in their DWC Res. Sure, they have automated their Top-off, but theyre burning through their media/membranes. Other more amateur growers are simply topping off by hand. This can be done of course, but its a pain in the ass, it drastically increases the workload, and your system isnt nearly as dialed and stable as it could be.

If your saying the tds creep that is occurring while the float valve is off is ruining the membrane than I apologize. So far everything I have been able to find about it refers to it depleting the di resin faster because it's getting that first 1/2 gallon of less than perfect ro pushed though it and that is the concern.

"Less than perfect" is a generous statement. Youre correct, but youre(not you literally) are blasting short bursts of exponentially higher TDS through your media and membranes. If by "less than perfect," you mean "extremely damaging," then agreed.

We don't use di as a last stage filter, and even if we did it would be only that first 1/2 gallon./QUOTE

Just depends on who you mean by "We". The proverbial "We," as in the entire Hydro community? I understand that most in the Hydro world arent running DI, but theres no reason why they shouldnt. An extra housing can be added to almost any existing RO unit for like $40. I should mention that I used to run Hardwater Tap in Hydro with good results, so none of this is critical, or necessary for the average grower. Thats not what Im claiming. But my end product quality in DWC skyrocketed after starting with pure water.

 

[MrAwder]

Thanks for the additional information. Still need to read through a lot of it. I installed a new membrane and plan on keeping full notes of readings, pre-filter changes and the life of the unit and make a decision for how to proceed from there.

Just to be clear my RO res is not in anyway connected my feed res. My RO res is ~40 gallon and I pull 30 gallon into 5 gallon buckets twice a week and mix my nutes in the 5 gallon. Then I manually fill my feed res with those 5 gallon buckets. So the system is typically kicking on (from the float valve in the RO res) to make about 30 gallons of new RO water, although I am sure it kicks on due to evap occasionally as well.

Still I think this thread has brought out a lot of really good information in regards to moderate scale RO production that I was not aware of and will definitely be of use if I find myself expanding or getting into reef aquariums. In both cases a new home would be in order first, hopefully with better starting water too!

 

[theother]

QUOTE=theother;6730840]Didn't have a chance to read it all but I will clarify' I don't think I was clear in the last post. Tds creep is happening because an ro is cycling on and off very regularly. The lamps make the water evap the ATO float goes down and the ro starts making water. Happens often and makes small amounts of water. The tds creep is pumped into the do resin depleting it faster.

Your understanding of what is happening is correct, however, who said anything about DI only being affected? This affects every stage.DI just happens to be the most expensive of the bunch.


Ours is different because we pull out 200 gallons and make 200 gallons. No on and off cycling in most hydro systems I have seen. If you did have a float set up to top off a hydro system as the plants drink it you would get tds creep. We of course will get tds creep while the system is off, and that first 1/2 gallon will have a higher tds than the rest, but it will be diluted by the next 200 gallons of water.

The way youre making water is the better way, for sure, but I assure you, not everybody is doing it this way. There are lots of guys plumbing their units straight into their Reservoirs to replace Evap and water loss from Plant uptake.

That's all I'm saying, the tds creep is caused by small volumes of water frequently coming out of the membrane. Hydro (at least in the sense we are all talking about) doesn't work this way.

I dont recall ever discussing specific methods of Hydro in this discussion. Weve just been discussing RO units and membranes/media. I would disagree with the statement that "Hydro doesnt work this way." It entirely depends on the method of hydro dude. For example, say you make a large batch of water for a large DWC operation. Any expert DWC grower will automate their water level replenishment to avoid too large of a PPM spike when the water level drops. Thats an entire other discussion, but theres not always going to be a symbiotic relationship between salts and water level based on what the plants are using. There are plenty of growers, who for convenience sake, are teeing off a water line from their main, straight into their RO unit, and then plumbing that to a float in their DWC Res. Sure, they have automated their Top-off, but theyre burning through their media/membranes. Other more amateur growers are simply topping off by hand. This can be done of course, but its a pain in the ass, it drastically increases the workload, and your system isnt nearly as dialed and stable as it could be.

If your saying the tds creep that is occurring while the float valve is off is ruining the membrane than I apologize. So far everything I have been able to find about it refers to it depleting the di resin faster because it's getting that first 1/2 gallon of less than perfect ro pushed though it and that is the concern.

"Less than perfect" is a generous statement. Youre correct, but youre(not you literally) are blasting short bursts of exponentially higher TDS through your media and membranes. If by "less than perfect," you mean "extremely damaging," then agreed.

We don't use di as a last stage filter, and even if we did it would be only that first 1/2 gallon./QUOTE

Just depends on who you mean by "We". The proverbial "We," as in the entire Hydro community? I understand that most in the Hydro world arent running DI, but theres no reason why they shouldnt. An extra housing can be added to almost any existing RO unit for like $40. I should mention that I used to run Hardwater Tap in Hydro with good results, so none of this is critical, or necessary for the average grower. Thats not what Im claiming. But my end product quality in DWC skyrocketed after starting with pure water.

Sick! So what I said did make sense. Lol honestly I post these always on the go and I'm never sure if I'm being completely clear.

When I say hydro I think I'm mostly referring to small to medium sized gardens using 30-300 gallons a week. Some methods seem to take a ton of water, I was amazed at how much dtw multi feed coco with small plants used. That was a challenge to keep up on. Many of the gardens here probably fall in the realm of 100 gallons per week. Made probably 55 gallons at a time.

Any tips to improve efficiency in that range is probably where most people would benefit.

I kind of think some kind of better pre filter or even a softener like someone mentioned above. It never even occurred to me that sodium or potassium would cause much less scale when rejected by a membrane than cal mag does.

Fwiw I do turn my unit off after it's done making water, lol, but it's cause it leaks at the float valve that's what's up with hydro my friend

Thanks for the additional information. Still need to read through a lot of it. I installed a new membrane and plan on keeping full notes of readings, pre-filter changes and the life of the unit and make a decision for how to proceed from there.

Just to be clear my RO res is not in anyway connected my feed res. My RO res is ~40 gallon and I pull 30 gallon into 5 gallon buckets twice a week and mix my nutes in the 5 gallon. Then I manually fill my feed res with those 5 gallon buckets. So the system is typically kicking on (from the float valve in the RO res) to make about 30 gallons of new RO water, although I am sure it kicks on due to evap occasionally as well.

Still I think this thread has brought out a lot of really good information in regards to moderate scale RO production that I was not aware of and will definitely be of use if I find myself expanding or getting into reef aquariums. In both cases a new home would be in order first, hopefully with better starting water too!

I'm with you for the most part. I would be willing to invest in some simple pre filter or softener that substantially extended he life of things. Maybe a softener first and then a booster pump hooked to one of the auto back flush controllers. My main focus is not wasting water and it seems like membrane efficiency and membrane life go hand in hand.

 

[BakedBandit]

Tds creep won't effect all stages, as most are before the membrane which is where the yds creep will come from. So mostly membrane and DI if its used. Of course those are the two most expensive stages!

 

[Pulsar]

Tds creep won't effect all stages, as most are before the membrane which is where the yds creep will come from. So mostly membrane and DI if its used. Of course those are the two most expensive stages!

Sorry, been working alot. Just saw this. So, for the record, the correct way to plumb a system, even if you're just running RO by the way, is
Sediment
Carbon
Chloramine( if your municipal tap has chloramines added. Most do.)
RO Membrane
DI( if used)
You're correct that DI is the main concern( along with chloramine filters)
By the way, standard flush kits, on ANY unit, are only flushing the Tap side. Still slightly beneficial, but anyone wanting truly pure water: consider adding more cartridges to your unit, run DI for the added polishing it achieves and absolutely install a DI bypass if you really want to lengthen your DI life. Most units will not come standard with a DI bypass, but it's as simple as throwing some John Guest fittings between the RO membrane and the DI. Here's a picture: the Tee allows me to not only eliminate TDS creep entirely before it hits my DI cartridges( I just turn off the valve on the left and bleed out the high TDS water out of the RO line with the Tee on it) but I can also hand test the TDS of my RO via my handheld bluelab meter , make drinking water or whatever else I want to isolate my RO for.

 

[queequeg152]

chloramine disinfection is the exception not the rule.

very large plants will run chlorine dioxode ejectors. smaller ones will run sodium hypochlorite.

water plants switch to chloramines for two reasons.... the least common is that the distribution system is unusually long and low in demand.

the most common reason for chloramine disinfection is that there is nasty shit in the water that reacts with hypochlorous acid, yielding an epa regulated disinfection byproduct.

chloramine costs more, and yields little compared to conventional disinfection... provided your plant is not run by retards.

 

[Pulsar]

chloramine disinfection is the exception not the rule.

very large plants will run chlorine dioxode ejectors. smaller ones will run sodium hypochlorite.

water plants switch to chloramines for two reasons.... the least common is that the distribution system is unusually long and low in demand.

the most common reason for chloramine disinfection is that there is nasty shit in the water that reacts with hypochlorous acid, yielding an epa regulated disinfection byproduct.

chloramine costs more, and yields little compared to conventional disinfection... provided your plant is not run by retards.

While the topic of treatment plant logistics is mildly interesting, I should reiterate that I'm personally not even slightly worried about Chloramines as they relate to growing bud. The topic at hand was strictly geared towards filter life. Ive grown in dirt for years with straight up unfiltered tap loaded with chloramines with nothing but outstanding results. The only reason I even run a Chloramine filter in stage 3 of my 5 stage is that I need it there for Aquaria, as Chloramines are toxic in reef aquariums. I do seem to notice a boost in quality when running DI in DWC, and I simply never run into algae or pythiium, but as far as dirt is concerned, I remain unconvinced it's necessary. Perhaps one justification of running DI in DWC is the inherent lesser population of beneficial microbes present with this growing method, but that is entirely anecdotal. I also run Organics so I personally prefer to start with as clean of a Res as possible. The system is also chilled to boost the DO content. At any rate, here's a photo of a recent grow of some of Bodhi's gear. Fed with Chloramine laden raw tap in dirt

 

[queequeg152]

what makes you think your municipality injects chloramine?
do you have a water quality report or some such UK equivalent that states this?

 

[Pulsar]

what makes you think your municipality injects chloramine?
do you have a water quality report or some such UK equivalent that states this?

Yes. They add Chloramines. In CA they are required to post multi-annual water quality reports with a comprehensive list of variables.
Again though, the Chloramine issue was more of an aside in this thread. It's simply not a major concern.

 

[theother]

I agree, except for filter life it doesn't really apply. Gotta change my charcoal in a few days, been doing sediments monthly. Really hoping to get some life out of this membrane. I'm making a lot less water so that should help, i did fix my compression on the float valve so the unit is always on now. Definitely gonna keep checking. It was easier to turn off and on when I was storing more, but it got out of hand space wise, cut it down to a third the storage.

Pulsar are you running multiple charcoals? Somewhere I think I have an old to unit that I could remove the membrane and use the other 2 pre filters in front of my current unit. Would let me run 2 sediments and 2 charcoals I guess. Can't recall if I have seen multiple charcoals.

Money's tight so I don't want to buy the booster pump back flush and on off solonoid right now, but that would effectively handle the tds creep puslsar was talking about but still be convenient. I believe it has a normally off solonoid valve before the pump. Can't quite imagine how it's sensing it from a float switch though if there isn't pressure to the unit. Maybe it doesn't work the way I think.