Rodi help

[Wildreefs]

Have the spectrapure 180 gpd. 3 canisters underneath, (sediment, carbon, Di) 2 90 gpd membranes above.

Unit was bought used in January, barely used. Membranes are rejecting 95 percent of water before DI.

Incoming tds from house is around 270. After membrane (sediment, carbon, membranes) 11 tds, then DI gets it down to 6 or 7. Di is about 10 days old, I’ve made less than 100 gallons good water with it.

Can’t be buying new di’s Every week.

Any advice?

 

[jaxredsoxfan]

Whats the pressure, if pressure is too low, the membranes not as efficient.

 

[lpsouth1978]

I agree with jaxredsoxfan. Your membrane should be rejecting ~98-99%. 11 TDS after the membrane is a bit high, but should not exhaust the DI resin that quickly. The resin may not be packed tight enough either. If it is too loose, it can let water channel through it and not everything will be removed.

My source water has a TDS of ~540 and after the membrane it is at 6. After DI it is 0. I have dual DI canisters and have to change the resin about every 4-6 months.

 

[JoshH]

Did you replace any of the filter media when you bought it? I would personally not trust any used media. Barely used is still used, if it was used or setup improperly the previous owner could have burned up the current filters.

And +1 on the PSI into the system.

 

[DesertReefT4r]

11 tds is high for a 270 source water. My source water is 480 and my over 1 year old Spectrapure 90gpd membrane is producing 9 tds, 3 when it was new and I am using the basic $40 membrane not the premium one.

 

[Wildreefs]

I changed the carbon and sediment 1 month ago, along with a DI I’ve had in shelf for 10 months to a year , still in package.

0 tds for about 1.5 weeks (150 maybe good gallons) and tds crept up. Was told by spectra maybe DI was shot from sitting for a year, got brand new one, 0 tds for one week, now up to 7 tds.

I understand 11 tds out of membrane is not great, but t shouldn’t rock my DI that fast.

Pressures is 64 .

I do have one membrane I could try and swap out. About a year old in package. See if I can bring down 11 tds after membrane. Can’t be buying DI every week especially on 50 gallon tank.

At that rate cheaper to buy at lfs

 

[Opus]

I don't think your membranes are the problem. You have an issue with the DI. At 11 tds, you should get around 400 gallons of 0 tds water from a di cartridge. As stated earlier, did you pack it down really well. I always pack it down as far as I think I can and then add more on top of that. Also, make sure you didn't install the DI cartridge upside down. I've done that before and I got 0 tds water for awhile and then it shot up even though the DI media wasn't exhausted. The only other issue I can think of is a CO2 issue. That is usually associated with well water.

 

[adrianr514]

CO2 could be eating your resin like candy. Test you waters CO2 levels.

 

[vetteguy53081]

Check to assure membranes are not backwards And that the valves are fully open

 

[Wildreefs]

These aren’t the diy or make yourself di’s. These are spectrapure di-sb-10hc Di cartidges.

 

[Mattman1977]

Maybe try a pre filled DI cart. That could tell you if your resin isn’t packed correctly. I could never get my resin packed tight enough it seemed until I picked up one of these nifty sponges from brs. https://www.bulkreefsupply.com/replacement-sponge-for-di-resin-cartridge.html

I just pack it as full as I can put the sponge on top and shove together. Not sure if it’s the correct way but seems to work for me.

I’m running a 90gpd spectrapure with 450tds source water and 6 tds out of the membrane and 0 after di. Get around 5 months on a di refill

Best of luck and happy reefing
Matt

 

[Mattman1977]

These aren’t the diy or make yourself di’s. These are spectrapure di-sb-10hc Di cartidges.

Never mind my last post if you’re using prefilled carts. I’m at a lose then. Have you tried a different rodi system? Maybe a fellow reefers in your area. If you’re around Charleston SC you can borrow mine.

Happy reefing
Matt

 

[Opus]

Can you post a link to your city's latest water quality report?

 

[laverda]

Take some of you water before your DI, test the PH, then airate it with outside air for an hour or so and test the PH again. If the PH changes much then you have high CO2 which is eating up your resin.