About ready to throw in the towel

[skunkmere]

Wow your membranes last you 6 years. i always change it out when it hits 5tds. chlorine is bad for membranes. i found this :

"For Dow FilmtecTM RO membranes, degradation can occur after roughly 200-1,000 hours of exposure to 1 mg/L of free chlorine. Unfortunately, chlorine damage is irreversible with any RO membrane, so proper steps must be taken to prevent it."

According to SpectraPure, chlorine will in fact degrade the membrane, and my maintenance account served as proof of this. We started with a new membrane with 002 Post-Membrane TDS. Only 5 years later, we were getting 016 Post-Membrane TDS... this is Downers Grove water containing total chlorine of 1.00ppm.

My personal system is in Sycamore, where we have zero detectable total chlorine in our tap, so I've never paid much attention to changing my carbon block. In fact, my new membrane also started at 002 Post-Membrane TDS, and I just changed it last month (6 years later) when it hit 003 Post-Membrane TDS (same sized system and water change frequencies).

Unfortunately, lack of monitoring and changing the carbon block in Downers Grove caused severe degradation of the membrane, and led to severe consequences in the tank.

From the thread I posted...

 

[dja1980]

Nice find... yeah, 6 years on my home system... and it was still getting 98% rejection. I think that's the difference of living in an area where there's no chlorine in the tap. The only reason I bought a new one on that system is because SpectraPure came out with their new 99% rejection membranes, and I figured the timing was right... and I might be able to save some money by not having to replace DI resin as often. I put my old membrane in a bag and stuck it in the frig... figured it still might be worth a few bucks to someone. We'll see how long I can get away with the one in Downers Grove now that I'm changing carbon blocks on that system every 3 months now... changed that membrane almost 2 years ago, and we're still getting 000 TDS Post-Membrane!

 

[skunkmere]

thats crazy. At work we have huge RO's 8GPM. and we replace the membranes after the production drops too much or when it hits 80% rejection. It makes me think that i may be changing out my membranes way too soon. its cheap though 30 bucks on ebay for a membrane, but a regular carbon change can keep it good longer. i always think about silicates breaking through, i have no idea if thats true.

 

[xtlosx]

So after a couple days with MicroBact7 my sand is getting white and I can actually see half of it again through the cyano as well as areas of my rock becoming visible again.

My situation, as much as dja is saying looks like something with my water, with all due respect I do not think it is involving the water. I change all of my filters out constantly not to mention this only flared up again when I moved a very large rock and likely stirred up a huge cycle. It's getting better but as we all know in this hobby, it just takes a lot of time and patience.

Question I have is, going into my DI resin I get 3TDS and coming out it's 0. Would it be worth calling my village and asking them if they can test my water for me? I don't really feel like changing filters constantly if that isn't the problem as I'm getting 0 TDS coming out although it seems like people don't trust that all too much.

What are your thoughts?

 

[markalot]

Are you taking a temperature corrected reading from the RO output, or using an inline meter?

My issue with not changing the sediment filter and Carbon Block on a regular basis is that there is not a good test to see if they are bad. You can use pressure for the sediment clogging, but the carbon block going bad just means bad things are making it to the RO which may or may not reduce it's life, and may or may not be removed by either the RO membrane or DI filter.

I would say replace the sediment and carbon block on a regular basis, RO only TDS out of it rises above the usual levels. I might also use Seachem Prime if I was worried about anything making it to the final product.

 

[xtlosx]

Are you taking a temperature corrected reading from the RO output, or using an inline meter?

My issue with not changing the sediment filter and Carbon Block on a regular basis is that there is not a good test to see if they are bad. You can use pressure for the sediment clogging, but the carbon block going bad just means bad things are making it to the RO which may or may not reduce it's life, and may or may not be removed by either the RO membrane or DI filter.

I would say replace the sediment and carbon block on a regular basis, RO only TDS out of it rises above the usual levels. I might also use Seachem Prime if I was worried about anything making it to the final product.

So I'm really only measuring or caring about what the TDS is going out of the DI Resin. I just changed carbon block(s) and sediment filter about 1-2 months ago. I will just order new filters just as a matter of good practice and to help rule that out.

I'm using the carbon blocks and sediment filter from BRS.. Does anyone use any specific brands that do a better job? At this point I'm willing to try anything.

 

[dja1980]

Question I have is, going into my DI resin I get 3TDS and coming out it's 0. Would it be worth calling my village and asking them if they can test my water for me? I don't really feel like changing filters constantly if that isn't the problem as I'm getting 0 TDS coming out although it seems like people don't trust that all too much.

What are your thoughts?

Honestly, I think your best bet is to pick up a Hanna Chlorine Checker and start testing your membrane waste and final output. This will give you a much better idea of what's getting past your membrane and DI filter(s). I can't stress enough that TDS meters are only good for relative measurement. If you don't want to purchase a meter (I think they're about $50), I'd be happy to lend you mine.

 

[skunkmere]

i dont think its your water. it might just be the detritus in your sand. i stir up my sand once in a while, i do have cyano and some wierd algea on most of my rock, i just blow it off and scrub off what i can. you might be just chasing your tail on this problem. can you post a picture. if you just changed out carbon and sediment filter i would rule that out.

 

[dja1980]

I don't think this can be ruled out until we know if any chlorine is sneaking past the membrane. Remember, membranes and DI resins aren't very effective at removing chlorine/chloramine, and if your membrane has degraded and is getting less than 98% rejection, your DI resin probably isn't lasting you more than 2 months or so. Also, if there is chloramine sneaking through, this would cause cyano outbreaks because you would be adding ammonia with each water change. This would explain why your new bacteria treatment is helping (speeding along the cycle, but you'll have to keep at it until you eliminate the ammonia).

Total Chlorine = Free Chlorine + Chloramine (Free Chlorine kills your membrane, Chloramine causes cyano outbreaks)

Here is a really good BRS video pertaining to chloramine and RO systems...

http://www.youtube.com/watch?v=xutc6GRvPTA&feature=share&list=PLBaMLrfToJyzroiJy9VRgO4nhm9S5Vbhw

 

[markalot]

So I'm really only measuring or caring about what the TDS is going out of the DI Resin. I just changed carbon block(s) and sediment filter about 1-2 months ago. I will just order new filters just as a matter of good practice and to help rule that out.

I'm using the carbon blocks and sediment filter from BRS.. Does anyone use any specific brands that do a better job? At this point I'm willing to try anything.

The sediment filter and carbon block protects the RO membrane. The RO membrane should be reducing your TDS to < 5 (it really depends on the source TDS since it's a percentage). The DI should reduce it to 0, NO EXCEPTIONS. Testing RO output is the only sure fire way to see if your RO membrane needs replaced.

A good DI can be used all by itself to produce 0 TDS water but it would need replaced on a frequent basis and they are one of the most expensive components. I like to think of everything in front of the DI as there to save me money. Take care of the front end and your DI resin will last a lot longer.

 

[dja1980]

+1... The downstream filters get more expensive down the line, and each step has a specific purpose... Sediment protects the Carbon from getting clogged prematurely... Carbon protects the Membrane from chlorine... Membrane protects the DI from TDS, DI does the final polish. If you let ANY of those steps get exhausted, you end up compromising the entire system. That's why you are also supposed to "rinse up" cartridges downstream when you replace a cartridge... due to the amount of TDS that gets released from new cartridges. Those DI cartridges are so sensitive to TDS... you can use up half their life just by replacing an upstream cartridge and not doing the rinse up procedure. If you have a MaxCap system, it even takes it a step further by adding a Pre-DI (MaxCap) after the Membrane to really make the Final-DI (SilicaBuster) last a long time.