Phosphates in RO/DI Water

M

mitch91175

Premium Member
Ok guys here we go. Currently I have been prepping my 240 for some new SPS that I have coming in hopefully on Monday. So about a week ago I started dosing vinegar to lower my nitrates in my DT. All is great everyone is doing well. No fish deaths and my RBTA are wide open with no signs of stress, etc.

I also switched my salt from Red Sea Coral Pro to Reef Crystals to save a little $$$. Besides, salt shouldn't contain phospates right and I am dosing kalk to maintain pH, calc, alk. Those parameters are fine in my DT. Also the tank has been running for 4 years. Initially had algae like most do so no worries.

Started noticing spots of algae growing in the DT and am wondering to myself what the heck. Decided to test my RO/DI water after adding the salt and crap PHOSPHATES (0.47mg/l)! Tested using a Milwaukee phosphate tester (more accurate to me). Testing my DT getting a 0.05 mg/l so not terrible (sure it won't be there shortly - unless I add the new salt mix without running it through GFO).

Also, on my RO/DI unit, everything was recently changed except the RO membrane, but felt that wasn't the issue since my TDS is reading 0. When I switch the TDS to see what I have coming in I get a reading 166+/-.

Do you guys think it could be the salt or the brute contain that is adding the phosphate to the new salt mix? Not gonna throw away the water just gonna run GFO on this batch of water the do some further investigating.

Plan on:

1. Running GFO on salt mix
2. Once phosphates read 0 will add to DT
3. Get some fresh RO/DI water and test it prior to adding the salt
4. If that test in step 3 is good, then will add the salt and test again
5. If that test isn't reading 0 then it must be the salt

I definitely do not want to go through another hair algae issue. Such a PITA.

Any ideas, suggestions?
 
Last edited:
The Milwaukee meter might work on RO/DI. If so, I agree with checking the filtered water, although that phosphate level is very high to read zero TDS on most meters I've seen. If the Milwaukee isn't rated for fresh water, I'd see whether there's a local fish store that could help. For now, I guess you'll have to try step 1. :(
 
bertoni said:
The Milwaukee meter might work on RO/DI. If so, I agree with checking the filtered water, although that phosphate level is very high to read zero TDS on most meters I've seen. If the Milwaukee isn't rated for fresh water, I'd see whether there's a local fish store that could help. For now, I guess you'll have to try step 1. :(
Click to expand...

I will take some water in the morning to an LFS for them to check. That is just strange that I am getting that reading on fresh mix. If the fresh RO/DI water at the LFS test positive for phosphates, then I will say that the culprit the the RO/DI unit. If not, then it is either the brute container or the salt mix. Curious which it is. I have read stories about people saying it was their salt, but now I am intrigued to find out.
 
Do you have chloramine in your tap water? I had terrible problems with algae and cyano until I found out that my tap water contains chloramine and I needed to add another filter to my RO/DI unit to get rid of them. I'm not sure about phosphates, but I know it's like adding ammonia to your tank if you don't filter it out.
 
ramseynb said:
Do you have chloramine in your tap water? I had terrible problems with algae and cyano until I found out that my tap water contains chloramine and I needed to add another filter to my RO/DI unit to get rid of them. I'm not sure about phosphates, but I know it's like adding ammonia to your tank if you don't filter it out.
Click to expand...

That I do not know. I did see that Texas has a greater than 50% chance of it. Gonna get a test kit to see.
 
ramseynb said:
Do you have chloramine in your tap water? I had terrible problems with algae and cyano until I found out that my tap water contains chloramine and I needed to add another filter to my RO/DI unit to get rid of them. I'm not sure about phosphates, but I know it's like adding ammonia to your tank if you don't filter it out.
Click to expand...

Found out really quick that we do in fact have chlormine in our water. Suggestions on what has been successful for you?
 
HA! I'm in New Braunfels, TX. So, howdy! I fought cyano forever before discovering that was my problem. I can tell when my filters need to be changed when I start growing algae. I knew it added ammonia (chloramine is ammonia+chlorine) which would turn to nitrate in my tank but that interesting that it would add phosphates as well, if that's what it is anyway.

Yeah, it's just one additional carbon filter you need. It's a different type of carbon that will filter out chloramines. Give Buckeye Hydro a shout and Russ will get you all sorted out.

EDIT: Oh yeah, I would look into what kind of parameters RC salt will give you. If you're carbon dosing for SPS, you're gonna want a salt with lower alk. I use ESV salt mix. It's a little more pricey and it's a four part mix, but it's the best IMHO. A lot of people seem to like Tropic Marin salt too.
 
Geez. Just tested my fresh salt mix and I have .40mg/l AMMONIA! Never even though of testing that for as long as I have been in the hobby.
 
ramseynb said:
HA! I'm in New Braunfels, TX. So, howdy! I fought cyano forever before discovering that was my problem. I can tell when my filters need to be changed when I start growing algae. I knew it added ammonia (chloramine is ammonia+chlorine) which would turn to nitrate in my tank but that interesting that it would add phosphates as well, if that's what it is anyway.

Yeah, it's just one additional carbon filter you need. It's a different type of carbon that will filter out chloramines. Give Buckeye Hydro a shout and Russ will get you all sorted out.

EDIT: Oh yeah, I would look into what kind of parameters RC salt will give you. If you're carbon dosing for SPS, you're gonna want a salt with lower alk. I use ESV salt mix. It's a little more pricey and it's a four part mix, but it's the best IMHO. A lot of people seem to like Tropic Marin salt too.
Click to expand...


Thanks ramseynb for pointing that out for me. I honestly would have never tested for ammonia in my fresh mix.
 
Ammonia is from your Chloramines. I have them too and make a lot of water, certainly solvable.

Tell us about your current RODI system, how it is setup, and how much water you use.
 
When you have chloramines you need to do two tests to confirm your RODI is working properly.

You will want to test the waste water for chlorine. You need to use a total chlorine kit. I like the hanna HI761 ULR Total Chlorine Checker.

The second test you have already figured out. Total ammonia post DI. Ammonia will pass right through all of the carbon and the membrane, it is up to the cation DI resin to remove it. It will eat up your DI and I would stop running your system until you have it resolved. You can use some prime in your makeup water to help but I would not be doing any large water changes. I'd even consider discarding the water if it isn't too much.

To break down chloramines you need catalytic carbon and contact time. High flow rates are your enemy so if you produce a lot of water you need a lot of carbon. One of the best filters out there is the Pentek Chlorplus carbon block. It's a 1 micron block.

To remove the ammonia component it is best to run a cation heavy DI cartridge in front of a second DI cart. I've had great success with Spectrapure's Maxcap high capacity cartridges.

Another issue with chloramines is that without the proper carbon block in it from the get go your membrane has been exposed to damaging levels of chlorine. Since chloramine doesn't break down rapidly like chlorine the membrane has been continuously exposed since being turned on for the first time.
 
tkeracer619 said:
When you have chloramines you need to do two tests to confirm your RODI is working properly.

You will want to test the waste water for chlorine. You need to use a total chlorine kit. I like the hanna HI761 ULR Total Chlorine Checker.

The second test you have already figured out. Total ammonia post DI. Ammonia will pass right through all of the carbon and the membrane, it is up to the cation DI resin to remove it. It will eat up your DI and I would stop running your system until you have it resolved. You can use some prime in your makeup water to help but I would not be doing any large water changes. I'd even consider discarding the water if it isn't too much.

To break down chloramines you need catalytic carbon and contact time. High flow rates are your enemy so if you produce a lot of water you need a lot of carbon. One of the best filters out there is the Pentek Chlorplus carbon block. It's a 1 micron block.

To remove the ammonia component it is best to run a cation heavy DI cartridge in front of a second DI cart. I've had great success with Spectrapure's Maxcap high capacity cartridges.

Another issue with chloramines is that without the proper carbon block in it from the get go your membrane has been exposed to damaging levels of chlorine. Since chloramine doesn't break down rapidly like chlorine the membrane has been continuously exposed since being turned on for the first time.
Click to expand...



This guy knows what he's talking about! Listen to him.
 
tkeracer619 said:
When you have chloramines you need to do two tests to confirm your RODI is working properly.

You will want to test the waste water for chlorine. You need to use a total chlorine kit. I like the hanna HI761 ULR Total Chlorine Checker.

The second test you have already figured out. Total ammonia post DI. Ammonia will pass right through all of the carbon and the membrane, it is up to the cation DI resin to remove it. It will eat up your DI and I would stop running your system until you have it resolved. You can use some prime in your makeup water to help but I would not be doing any large water changes. I'd even consider discarding the water if it isn't too much.

To break down chloramines you need catalytic carbon and contact time. High flow rates are your enemy so if you produce a lot of water you need a lot of carbon. One of the best filters out there is the Pentek Chlorplus carbon block. It's a 1 micron block.

To remove the ammonia component it is best to run a cation heavy DI cartridge in front of a second DI cart. I've had great success with Spectrapure's Maxcap high capacity cartridges.

Another issue with chloramines is that without the proper carbon block in it from the get go your membrane has been exposed to damaging levels of chlorine. Since chloramine doesn't break down rapidly like chlorine the membrane has been continuously exposed since being turned on for the first time.
Click to expand...

Definitely appreciate the guidance. Have a Hanna tester on the way. What do you suggest that I do with the current batch of fresh salt mix. I tested for phosphates and this morning the batch is reading 0 :D. Now for the ammonia reading. Do you think I can just add some prime to the water and call it a day? I have never added prime to my fresh mix after I initially setup the tank. Just do not want to have the prime cause any issues if added to the mix then to the tank.

I did have a BRS Universal 1 Micron Carbon Block that I had recently ordered that also removes both Chlorine and Chloramine. So my 5 stage is setup like this now:

Chamber 1. GE ROSave.Z 1 Micron Depth Filter
Chamber 2. BRS Universal 1 Micron Carbon Block
Chamber 3. Older BRS 5 Micron Carbon Block (Chlorine removal only - will use the same in chamber 2 when it comes in)
Chamber 4. DI Resin

I am also considering adding a 5th chamber, but do not feel at the moment it is necessary since it will mainly be a back DI Resin chamber.

Thoughts?

Edit: Changed my mind and i will go ahead and add the 5th chamber.
 
Last edited:
Most filter setups will work for chloramine:

http://reefkeeping.com/issues/2003-11/rhf/feature/index.htm

Mine did. You could check the output of the RO/DI to see whether the TDS is zero, and if you're very worried, an ammonia test might be fine. Most salt products have ammonia as a contaminant, and the output from RO/DI should be a small fraction of that. I wouldn't worry much yet, but checking is easy and problems, while very rare, do occur.
 
Something Randy's article doesn't take into account is that when you are relying on the DI to pull the chloramines from the RO life is dramatically reduced on all of the filter carts, you might as well burn money each time you make water.

It certainly is a cause for concern and you should take the extra precautions, especially if you have a ph above 7.5. This is where the membrane stops efficiently rejecting ammonia. Even if you are at 7.5 or lower a lot of municipals are running 3.5 to 4.0ppm of chloramines, which would result in around .3ppm ammonia getting through.

You want your chloramine specific filter directly after the sediment filter. Your sediment filter needs to be rated at or better than your finest micron carbon block to prevent fouling. Run your standard carbon block(s) after the chloramine filter to polish the water. If you have 3 carbon blocks run two chloramine specific blocks. The more catalytic carbon the better.

Make sure your DI is up to snuff. Running a cation heavy DI (like maxcap DI cart) in front of a mixed bed will give you great results.

In my case (8.5ph) I increased my DI life by a factor greater than 10 by changing my setup to specifically target chloramines.

mitch91175 said:
What do you think about these: 3 X NSF Certified Compressed Carbon Block Filter, CTO Purity MAX,10", 1 Micron, WWC101 - 3 Pack. I have a few left and do not want to trash them. Maybe I will just run them in chamber 2 and move the current one in chamber 2 to chamber 3.
Click to expand...

I don't know much about these but if I would run two chloramine specific blocks if you have 3 chambers for carbon. If you have multiple membranes and a booster pump I would change out the primary carbon block to a larger canister. I'm using a 20BB sized chlorplus filter, which has lasted two years and is still producing water. This carbon block has saved me a ton of money in the long run.

mitch91175 said:
Just added a capful of prime to the water. Will shut off until I get the new filters in.
Click to expand...

Good call.

mitch91175 said:
Going to add this as the last 2 stages and use the exiting somewhere else: DUAL DEIONIZATION CANISTER WITH TRM-1 TRIPLE TDS METER unless something else is recommended. BRS pricing plus the $$$ applied to additional orders is great.
Click to expand...

Consider this. The heavy cation maxcap cart will remove more ammonia and save your mixed bed cartridge. You will not be replacing carts as often. nothing wrong with the BRS setup, if you go that way consider replacing the first stage with a maxcap when it is time to replace carts.
http://spectrapure.com/RO-RODI/ADD-ONS/MaxCap-D2-Dual-Stage-DI-System-Add-On-w-SuperDI-Cartridges
 
Last edited:
Here is a thread I put together a few years ago (almost 3) when I added the chlorplus 20BB.

I've probably made over 12,000gals of RODI at a 4:1 ratio. That means this filter has withstood 60,000 gallons of chloramine treated water. Can't tell you how many regular 10" filters I would have gone through in that time frame. The only filters I have changed are sediment and DI. I get about 2000 gallons out of my DI, vs about 200 prior to the switch. My municipal treats at 4ppm chloramines.


http://www.reefcentral.com/forums/showthread.php?t=2483520
 
You must log in or register to reply here.

Similar threads

D
Corals slowly dying / getting white spots water tests good
Replies
18
Views
635
griss
griss
S
Phosphate flow out of live rock
Replies
0
Views
699
SantaMonica
S
A
Salt water in wood
Replies
6
Views
406
C.Eymann
C.Eymann
J
Calcium very elevated
Replies
3
Views
803
jcarlilesiu
J
erb
question on salt creep
Replies
6
Views
784
kfisc
kfisc
Back
Top