High TDS after RODI

[spuri87]

Hello All, I have a month old RODI setup, nothing too fancy, just a simple 4 stage RODI setup I got from Amazon (https://www.amazon.com/Aquatic-Life-Changing-Deionization-Cartridge/dp/B00204CQF6/).. At the time of install I checked my TDS after the entire RODI process was around 1-5, compared to over 200 for tap water.. But now, TDS is at around 35 in my RODI barrel.. I checked TDS after RO stage (before DI) and it was around 50 and then after DI stage it came out to be at 20.. Seems like sitting water can get oxygenated and stuff which may raise the TDS further, which may explain the increase from 20 to 35 for the water sitting in my barrel.. But there is no way resins are spent within a month, so don't know what caused the increase from 1-5 to this high number in a month's time.

My phosphates have been high since day 1, sitting in 0.4-0.5 range.. I am sure my silicates will be high too since I see a little bit of diatoms on the rocks and sand.. A few days back I changed about 20% water hoping to see lower phosphates, but that didnt help at all.. Instead My Powder Blue and Hippo tang showed signs of mucus cones (short video posted here:

).. These usually happen when the fish is under distress and I have no idea if changing water had to do anything with it or not, but that was the only change I did, so I am questioning if the water quality has to do anything with it.

I am in San Jose, and just searched about SJWater using Chloramine (https://www.sjwater.com/notification-treatment-change) and quote the following on their website:

"Live Fish or Other Aquatic Animal Owners: Chloraminated water may be toxic to fish and other aquatic animals. If you maintain a fish tank or aquarium, ensure that the chemicals or filters you use are suitable for water treated with chloramines. You may need to change your filtration system to accommodate this change."

Seems like another Carbon stage maybe required to be added in the RODI system to help treat Chloramine.. Can folks share their knowledge and experiences with RODI setups and water quality? What is a good TDS number and how many stages in RODI system are y'all using?

 

[Alexander1312]

Not sure if you saw this, but for the past few days, we discussed the topic of chloramine removal here.

Challenges in removing chloramine in RODI setup

I didn’t see any steak house vouchers @Alexander1312 ? I turned back to being a meat eater haha—just joking. The vouchers are still available; I’m simply waiting for the right moment to pull them out again :).

www.bareefers.org

I will add a few more details later today.

In your case, if you did not use catalytic carbon in your prefilter, your membrane might be severely damaged by chloramine. The resins will then need to work much harder and rapidly deplete.

P.S.: The link to the product states explicitly that chloramines are not being removed by the type of carbon. I had this brand before and they are selling a different type of carbon for this same setup.

AquaticLife 10-Inch Sediment Water Filter Replacement Cartridges Kit (Carbon Plus Chloramine) https://a.co/d/9FvhJsn

 

[spuri87]

Just went through your thread.. thanks @Alexander1312 .. do you think the membranes are already damaged within a month which might be causing the increase in TDS? Do you think adding another Catalytic Carbon stage will help fix the high TDS issue or do you recommend upgrading the entire setup to like a 7-stage BRS setup?

 

[H2OPlayar]

Just went through your thread.. thanks @Alexander1312 .. do you think the membranes are already damaged within a month which might be causing the increase in TDS? Do you think adding another Catalytic Carbon stage will help fix the high TDS issue or do you recommend upgrading the entire setup to like a 7-stage BRS setup?

7, or something. It depends on your water in a bit and what you want to delete first.

 

[iani]

Just went through your thread.. thanks @Alexander1312 .. do you think the membranes are already damaged within a month which might be causing the increase in TDS? Do you think adding another Catalytic Carbon stage will help fix the high TDS issue or do you recommend upgrading the entire setup to like a 7-stage BRS setup?

This is the one I got a while back. You can always change out a filter or 2 for chloramines. https://www.amazon.com/dp/B01HOJ55RC?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_4

 

[Thales]

Is your DI resin exhausted?

 

[Alexander1312]

Just went through your thread.. thanks @Alexander1312 .. do you think the membranes are already damaged within a month which might be causing the increase in TDS? Do you think adding another Catalytic Carbon stage will help fix the high TDS issue or do you recommend upgrading the entire setup to like a 7-stage BRS setup?

First, the filter I recommended might not fit your system. They might actually not offer a suitable carbon for your system but please check.

I would replace the carbon first and measure TDS past RO. If the rejection rate is still only at 75% as it currently seems to be, the membrane is probably no longer working (should be at least 90%, up to 99%!).

 

[Alexander1312]

To Rich’s point, as I mentioned above, your DI resins are most likely depleted, but the question is why. As I said, the carbon does not break down chloramines effectively, impacting the membrane which impacts the DI. This would be my working assumption.

If you are looking for a totally new RODI, I would connect with Andy / @ReyDeFarts and chat with him.

 

[iani]

To Rich’s point, as I mentioned above, your DI resins are most likely depleted, but the question is why. As I said, the carbon does not break down chloramines effectively, impacting the membrane which impacts the DI. This would be my working assumption.

If you are looking for a totally new RODI, I would connect with Andy / @ReyDeFarts and chat with him.

Even if DI is exhausted TDS seems very high after the RO to me.

 

[iani]

First, the filter I recommended might not fit your system. They might actually not offer a suitable carbon for your system but please check.

I would replace the carbon first and measure TDS past RO. If the rejection rate is still only at 75% as it currently seems to be, the membrane is probably no longer working (should be at least 90%, up to 99%!).

Nevermind, you already answered this.

 

[spuri87]

First, the filter I recommended might not fit your system. They might actually not offer a suitable carbon for your system but please check.

I would replace the carbon first and measure TDS past RO. If the rejection rate is still only at 75% as it currently seems to be, the membrane is probably no longer working (should be at least 90%, up to 99%!).

Thanks, this is a good test.. I believe this is what would fit my system if I need to go activated carbon route: https://www.amazon.com/Aquatic-Life-Filtration-Particulate-Chloramine/dp/B0CZVM5HJ9

But I guess its better to see why TDS is so high after RO, so will just replace the Carbon for now to confirm. Thanks everyone for valuable input

 

[PjFish]

I would have questioned the 1-5 tds when you first hooked up the rodi system but if canisters are not stored correctly and or old they will deteriorate on the shelf. You would have had issues with all your other livestock at the beginning or by now if chloramines were a serious issue.. Not knocking Aquatic Life but based on your water quality it may not be a good fit for you plus their proprietary filters make it very limited..You’ve invested in a really nice tank & live stock and off to a great start! But the RODI your using is literally the cheapest unit on the market which plays a large role helping to succeed in this hobby.. Id return the unit if you can and go with a name brand with universal housings so you can upgrade if needed.. Your tanks still super new which their may be other factors at play .. Their are several other reefers who use the buddy and have good results but really depends on ur water..Hows all your other livestock doing and corals?

 

[spuri87]

thanks for your reflection on this @PjFish .. RODI was the 1st thing I ordered after I ordered my tank and didnt truly understand how important a role this will play.. I was told RODI is RODI system, just throw and replace it after an year.. I started looking at BRS 5 stage now, which I believe should be ok for my situation, 7 stage maybe an overkill tbh, with 2 extra DI but will keep researching.. But first, I really want to understand what's going on so that I can prevent this from happening when I go with a better RODI system

 

[Alexander1312]

Thanks, this is a good test.. I believe this is what would fit my system if I need to go activated carbon route: https://www.amazon.com/Aquatic-Life-Filtration-Particulate-Chloramine/dp/B0CZVM5HJ9

But I guess its better to see why TDS is so high after RO, so will just replace the Carbon for now to confirm. Thanks everyone for valuable input

I am not sure if this will fit to your existing setup tbh.

Also, fully agree with @PjFish sentiment. I did miss are running a larger waterbox so this RODI is definitely not proportionate to your tank, specifically if you need to make more water.

 

[Thales]

I would really check your DI resin, and see how your RO is performing. It is a small unit - what color is the DI resin (you are supposed to have gotten color changing resin).

How much water have you made on this unit so far? Is it leaking somewhere?

FYI, my tds out of the tap is like 30, and I have to replace my DI every 1-2 months. The DI is much more consumable than the RO.

 

[spuri87]

You would have had issues with all your other livestock at the beginning or by now if chloramines were a serious issue

So the water was added to the tank for over 2 weeks before livestock was added.. I got live rock so maybe they took care of the extra Ammonia added as part of the Chloramine in water? Just a guess.. my Hippo tang is still scratching itself every 10-15 mins, though PBT is alright now after I added Carbon 0.8 Rox which again might have done the same job as activated carbon in RO system.. This is all so interesting and overwhelming at the same time

 

[spuri87]

I would really check your DI resin, and see how your RO is performing. It is a small unit - what color is the DI resin (you are supposed to have gotten color changing resin).

How much water have you made on this unit so far? Is it leaking somewhere?

FYI, my tds out of the tap is like 30, and I have to replace my DI every 1-2 months. The DI is much more consumable than the RO.

that's a really useful data point you have shared here for your setup.. I will share a pic of how it is looking right now in a bit.. Though that doesn't explain why RO water had a high TDS (over 50) before DI stage

 

[Alexander1312]

So maybe going back to the drawing board on what you are trying to resolve.

You have a) relatively high TDS and b) chloramine in the water which needs to be removed, depending on your water suppliers reports, if high also PH, might be even harder to remove than it is already compared to chlorine (as it is in my case).

The sediment filter will remove a lot of the initial dirt. Replacing this frequently is not expensive but important to protect to next stages which are more expensive to replace.

Next, a chloramine ready carbon might take out most if not all of the chloramine. But it is not guaranteed. You could even consider adding another carbon stage after this.

Next, the RO membrane comes into play and with the right water pressure should remove 90-98% of the remaining TDS eventually.

So if you have 200 TDS, you can still end up having 15-20 TDS coming out of your RO membrane which the DI has to clean.

Based on the above, having at least two stages of DI in your case should make sure you are having 0 TDS consistently. You could go mixed bed for simplicity for both.

 

[spuri87]

So maybe going back to the drawing board on what you are trying to resolve.

You have a) relatively high TDS and b) chloramine in the water which needs to be removed, depending on your water suppliers reports, if high also PH, might be even harder to remove than it is already compared to chlorine (as it is in my case).

The sediment filter will remove a lot of the initial dirt. Replacing this frequently is not expensive but important to protect to next stages which are more expensive to replace.

Next, a chloramine ready carbon might take out most if not all of the chloramine. But it is not guaranteed. You could even consider adding another carbon stage after this.

Next, the RO membrane comes into play and with the right water pressure should remove 90-98% of the remaining TDS eventually.

So if you have 200 TDS, you can still end up having 15-20 TDS coming out of your RO membrane which the DI has to clean.

Based on the above, having at least two stages of DI in your case should make sure you are having 0 TDS consistently. You could go mixed bed for simplicity for both.

Thanks @Alexander1312 .. are you suggesting just add a DI stage to bring the TDS down and not worry about adding Activated Carbon stage? or do both? I dont know if there is Chloarmine present after DI stage since I never tested that, I just know that my tap water is treated with it by SJWater!

 

[Alexander1312]

I would really check your DI resin, and see how your RO is performing. It is a small unit - what color is the DI resin (you are supposed to have gotten color changing resin).

How much water have you made on this unit so far? Is it leaking somewhere?

FYI, my tds out of the tap is like 30, and I have to replace my DI every 1-2 months. The DI is much more consumable than the RO.

It is clear that the DI is exhausted. But this is more likely just a symptom, not the root cause.

For comparison - I have 27 TDS water and I am at 2500 gallon on my three-stage DI and they are used by less than 30%.

Let's not forget his carbon does not filter out chloramine, as stated on the product page. DI seems to be able to filter out chloramine but apparently (based on my discussion with Chris from airwaterice.com) this uses a significant amount of DI media vs getting this removed in the prefiltration stage already.