Adding a second carbon block filter

[Dramad1]

I have a spectrapure 90gpd ro/di referbished system. I have been thinking of adding an extra carbon block to my unit.

Can I just get an extra individual canister and run it before the unit itself? I would be turning that canister into a sediment filter canister and then run the second carbon block in the canister that used to house the sediment filter. Because the di is the last stage in the system, I'm thinking this would be the easiest way to do it without having to replumb everything.

I have also seen a dual canister add on kit, but it is labeled for a max cap system, would this unit work with the 90gpd referbished unit? If so would I be able to simply add a second carbon block as well as second di cartridge with out having to modify my current system to much? Also by adding the extra canisters, will this effect my gpd?

I have one other question unrelated. I plan to replace the membrane in the unit after filling my new tank and water storage containers, it has been a few years and has never been replaced, I plan to go with the 99% rejection rated 90gpd membrane. Will I have to mess with the flow restrictor at all? Sorry if this is a dumb question.

Az, lil help please

[AZDesertRat]

Adding a second carbon block is taking a step backwards. You are far better off with one high quality carbon block since everything n front of the membrane has an associated headloss which reducces the membrane efficiency and is an additional cost to replace each time.

Spectrapure has spent decades testing every possible combination of filters and sizes and their systems are the most efficient you can buy just the way them come from the factory. Stick with a single 0.2 or 0.5 micron sediment filter and 0.5 micron carbon block for best performance and life.

 

Before replacing your membrane test the rejection rate to see if it is needed or not. If the rejection rate is still in the 97-98+ range you will not gain much if anything by replacing it at this time. As long as you keep up with filter replacements using the same quality filters Spectrapure provides and you do at least an annual disinfection it is possible your membrane can last 10 years or more. Mine is 7 years old and just as efficient as the day I bought it, 99.4% rejection rate.

 

If you do replace the membrane it is wise to also replace the flow restrictor and trim it to the required waste ratio for your water conditions once you test it in place.

[VW_TDI_02]

If you do want to add an extra carbon block then all you have to do is add the canister before the rest of the filter. You move the sediment filter to the newly added canister filter and you can pop in the second carbon filter where the original sediment filter was. Pretty much you're going sediment filter (in the newly added canister) -->1st carbon filter (where the sediment filter originally was)-->2nd carbon filter. In this set up the first carbon block is going to need to be replaced before the second one so what you do is simply toss the 1st carbon filter and in its place put the carbon filter that was in the 2nd carbon filter block. You then add your brand new carbon filter as the 2nd carbon filter.

 

[Edit]

Just reread your original post and realized that I repeated a lot of what you already said/know. haha.

[Dramad1]

Adding a second carbon block is taking a step backwards. You are far better off with one high quality carbon block since everything n front of the membrane has an associated headloss which reducces the membrane efficiency and is an additional cost to replace each time.

Spectrapure has spent decades testing every possible combination of filters and sizes and their systems are the most efficient you can buy just the way them come from the factory. Stick with a single 0.2 or 0.5 micron sediment filter and 0.5 micron carbon block for best performance and life.

 

Before replacing your membrane test the rejection rate to see if it is needed or not. If the rejection rate is still in the 97-98+ range you will not gain much if anything by replacing it at this time. As long as you keep up with filter replacements using the same quality filters Spectrapure provides and you do at least an annual disinfection it is possible your membrane can last 10 years or more. Mine is 7 years old and just as efficient as the day I bought it, 99.4% rejection rate.

 

If you do replace the membrane it is wise to also replace the flow restrictor and trim it to the required waste ratio for your water conditions once you test it in place.

Thanks AZ, I am currently using the .2 zetazorb sediment filter and a .5 carbon block filter, next month they will be 6 months old. I'm still showing 0 tds after di, I will have to check before di and see what my waste ratio is again before hitting checkout on that new membrane. I like to flush and replace my filters every 6 months and usually di is due shortly after.

I have been making alot of water this last month and sediment and carbon filters are due for a change nxt month so, I thought I would go ahead and upgrade the membrane as well, but I see your point, if it's still good, why replace it.

I was under the impression that adding another carbon block would extend the life of the membrane as well as help remove chlorimines, my local wd uses chlorine. Just trying to put the best water in my tanks at this point. Maybe just switch the type of carbon block for one that removes clorimines?

[AZDesertRat]

The 0.5 micron carbon block is more than sufficient to remove the chlorine portion of chloramines and to break the bond with the ammonia so the membrane and DI can remove it. The DI is actually the key to good chloramine removal not the carbon. Spectrapure has done much testing on this and if it was not effective they would change their systems. Their 25+ years in RO/DI research and development can't be beat.

 

I run my ZetaZorb and 0.5 carbon block for 12-18 months and never have issues with plugging or fouling and headloss. I monitor my pre and post filter PSI using inline pressure gauges and monitor for chlorine breakthru using a low range chlorine test kit. If the carbon was exhausted the kit would catch it. You might not need to change your filters that often if you monitor their conditions and can save yourself some money. Phoenix water is hard as a rock and high TDS but the suspended solids are very low. A softener takes care of the calcium carbonate hardness and the RO/DI takes care of the TDS and the sediment and carbon don't have to work as hard since the TSS is low.