Phosphates increased after 20% water change

[dcox88]

I did a 20% change yesterday with RO water from my LFS. About 1 hr. after the water change, I tested the water. Nitrates were down, but phosphate went up. Any clues?

 

[nacl-h2o]

RO water frequintly has PO4(phosphates) in it. If the water going in the unit had very high PO4 the output water could have alot of PO4 in it. I would check the levels next time I purchase to make sure it's not common there is a high level in their water.

 

[donkeykong]

My guess would be your LFS filter pads need to be changed on there RO unit. Try getting the water from them and testing it before you add to your tank. Or even have another LFS test your water

 

[dcox88]

You are kidding!!!! I thought that was one of the biggest reasons to use RO. How can I bring phosphates down then?

 

[nacl-h2o]

If the media is changed regularly and the water going in isn't just saturated with PO4, it is a good water to use, but many people use RO/DI units instead because it removes far more PO4 than RO and in some areas depending on the PO4 levels in the local water, it's a big difference. If you never had a problem before they may just need to change their membranes, but I would test there water on a regular basis, just to be on the safe side.

 

[dcox88]

This is my first SW tank - and that was my first water change. Is there any other way to decrease the PO4?

 

[nacl-h2o]

You could try a Phosphate sponge, Seachem and kent make one amoung I'm sure others. This would be sold at most LFS and most online stores that sell dry goods. You might try Distilled water from Wal-mart or the grocery store for your next change if their water turns out to be a problem. GL

 

[dcox88]

I have read that the distilled water is good as long as it is not distilled using copper tubing. How can you be sure which brands don't use copper?

 

[muckworm]

Be careful about purchasing water from the grocery store or wal-mart... they can contain high levels of silicate which is almost just as bad as phosphates...

 

[nacl-h2o]

When I decided to start using Distilled I called the bottler of Wal-Mart's Great Value brand distilled water. They stated copper pipes are not used anymore for distilling due to water quality issues and federal requirments and they doubt very seriously anyone uses copper for distilled water made for drinking. After that I ran numerous test repeatedly(NH4, NO2, NO3, PO4, SiO2, Cu) for over a year and never found anything worth mentioning and have not had any issues from it's use (4 years now). I have also used and tested water from from two local grocery stores (Winn Dixie & Food Loin's generic brands) with the same result.

 

[frankl15207]

Originally posted by dcox88
You are kidding!!!! I thought that was one of the biggest reasons to use RO. How can I bring phosphates down then?
As mentioned by donkeykong, the problem is with the RO filters not being changed, not RO water in general. If the filters are exhausted, nothing is being removed from the water.
NaCl-H2O's comment on distilled water is also correct to my understanding. Copper is no longer used in the distillation process, primarily due to federal regulations. Most RO units now claim to produce water that is "as pure as distilled."

 

[nacl-h2o]

I haven't been shopping around for RO, RO/DI or DI units in awhile. It was my understanding that when it came to purity it went RO, then DI, then RO/DI, then Distilled at the purist. Are you sure it's the new RO units that make that claim and not the RO/DI? I knew thats why they added the DI portion to the RO units was to bring there water purity close to that of distilled.
Even if they they do, I doubt that the LFS has a brand new top quality RO unit and meny LFS use a RO unit like those you would buy at Lowes or Home Depot and they are defenatly not up to a reefkeeping purity.

 

[frankl15207]

You are correct. I missed the DI last night. It was late .