RODI unit questions

Fishingandreefing · Dec 25, 2019

Merry Christmas to everyone!

So I got an Aquatic Life 100GPD rodi Unit since April of 2018. I replaced the first two stages, sediment and carbon filters a couple months ago. The TDS reading is at or below 4.

according to aquatic life I don’t need to replace the rest till reading of 5 or more.

it usually takes almost 2 hours to produce a bucket. Isn’t it too slow compare to the 100GPD and I need to replace rest of the filters?

100 gallon divided by 24 hours = 4.17 gallon per hour?

Quietman · Dec 26, 2019

Take a look at the ratings on the RO membrane. They are usually 50 or 60# at 77F. Plus there's back pressure and yes TDS. Rarely will you find someone hit the rated production due to those prerequisites. I usually fill about 10 gallons in 3.5 hours.

Is that 4 TDS output of whole system or just the pre DI stages? Seems a tad high if you're taking output of DI resin beds.

Fishingandreefing · Dec 26, 2019

Quietman said:
Take a look at the ratings on the RO membrane. They are usually 50 or 60# at 77F. Plus there's back pressure and yes TDS. Rarely will you find someone hit the rated production due to those prerequisites. I usually fill about 10 gallons in 3.5 hours.

Is that 4 TDS output of whole system or just the pre DI stages? Seems a tad high if you're taking output of DI resin beds.

4 is with all the stages installed. The membrane and DI will be two year in April.

Quietman · Dec 26, 2019

Fishingandreefing said:
4 is with all the stages installed. The membrane and DI will be two year in April.

4 is probably fine, I'm usually not usually OCD about anything, but if my RODI is going into storage/saltwater mixing over 0 I'm finding out why in short order.

I have a 3 stage DI resin and I burn through anion much faster than cation or mixed and am replacing it every 200-300 gallons (that's about 2-3 months for me). It's color changing so easy to tell. After 7 months I have yet to replace the cation or mixed bed (and actually, they only have a minimum of color change and should last another year or more).

scottedontknow · Dec 26, 2019

4 tds is high, you should be getting 0 tds in your final product water. What kind of PSI are you getting going to the unit? If you’re below 60ish you may want to get/look into a booster pump. I’ve never used/saw the Aquatic life ro system so I don’t know their exact specs.

Fishingandreefing · Dec 26, 2019

Quietman said:
4 is probably fine, I'm usually not usually OCD about anything, but if my RODI is going into storage/saltwater mixing over 0 I'm finding out why in short order.

I have a 3 stage DI resin and I burn through anion much faster than cation or mixed and am replacing it every 200-300 gallons (that's about 2-3 months for me). It's color changing so easy to tell. After 7 months I have yet to replace the cation or mixed bed (and actually, they only have a minimum of color change and should last another year or more).

I will wait till reach 5 or till April for total of 2 years for the replacement. Just don’t want to throw away $60 because it’s slightly high and lower produce rate.

Fishingandreefing · Dec 26, 2019

scottedontknow said:
4 tds is high, you should be getting 0 tds in your final product water. What kind of PSI are you getting going to the unit? If you’re below 60ish you may want to get/look into a booster pump. I’ve never used/saw the Aquatic life ro system so I don’t know their exact specs.

4 is high really? I would say 1 hour 45 mins for a bucket

Quietman · Dec 26, 2019

Fishingandreefing said:
I will wait till reach 5 or till April for total of 2 years for the replacement. Just don’t want to throw away $60 because it’s slightly high and lower produce rate.

I get that. Part of it's my water...very high TDS and whatever is burning through Anion. I was having to replace a two staged mixed every 2 months or less, that was getting pricey.

Fishingandreefing · Dec 26, 2019

Just replaced the DI cartridge and checked it was only like $20 I paid. According to Aquaticlife DI needs to be replaced a lot sooner or the color is completely changed.

now flow rate is about the same but 0 TDS

Just flushed the first half gallon and it was good to go!