phosphate and salt mix

[sarajo]

Ok I decieded to do some phosphate testing today, done with a hanna photometer.
Ro Di water; .02
Mixed with Reef Crystals: .37
Mixed with ESV bionic salt: .28
Whats going here? I first tested both salt mixes and thought my DI resin had gone bad but when I tested the ro water it came out to .02. any ideas on what is happening, I've tested both salts before and neither was over .05.:squigglemouth:

 

[seth&angelle]

I'd question the hanna meter. You should have absolutely no phosphates in RO/DI water, assuming it is running properly.

 

[stunreefer]

So you tested RO and it was .02, what was the reading after the DI cartridge?

RO/DI will contain some levels of phosphate. You can run the DI effluent through GFO, although I never have. Generally the amount is negligible, which in your case sarajo it is not. Also keep in mind that all salt mixes will contain trace amounts of phosphates, but I wouldn't ever expect that much.

 

[sarajo]

yeah the .02 was after the DI stage. anybody have any ideas on any other test kits that would be good? When I tested the salt mixes you could tell that the liquid in the sample jar had a blue tint to it after the 3 minutes of waiting, so I fully expected the rodi water to test high but it didn't, go figure.

 

[AZDesertRat]

What DI resin are you using, is it tightly packed in a vertical DI cartridge filing from the bottom up, how old is it and what is your TDS reading directly from the RO/DI. A good RO/DI should not have any phosphates present in the treated water period. Good resin and contact time are a must since phosphates are weakly ionized and are not readily removed.

Does your water utility feed phosphates for corrosion control in the water distributiion system? Many do so its worth checking. If so get yourself some good resin like Spectrapures SilicaBuster which is designed specifically with phosphates, silicates and niitrates in mind unlike most common mixed bed resins it is custom blended in house by Spectrapure for reef hobbyists.

 

[stunreefer]

What are you using to mix your saltwater in? Do you clean them frequently? How long have they been used? (I'm thinking maybe you're leaching from somewhere).

Did you run the test multiple times? The Hanna photometer is the best out there really. Do you use the older model or the new "checker" model?

 

[stunreefer]

A good RO/DI should not have any phosphates present in the treated water period.

Interesting! I've always seen a small amount (~.03 or below) of phosphate once my DI is "half shot" (which is when I see about 1/2 of the color changes). Looks like I'll be picking up a SilicaBuster for my next DI change

 

[sarajo]

I have the older model, i mix the saltwater in old salt mix buckets I never had any test no where near that high before, I did not test multiple times but I tested my display tank and the rodi water right after the salt mixes and the display was .05 and the rodi was .02. I just changed all filters except the ro membrane on the filter and its reading .03 after letting it run for about 1 hour.

 

[AZDesertRat]

Stunreefer, never depend on color changing resins, they are a very poor indicator of resin condition and are usually shot before the color turns. Always us a good handheld TDS meter like the HM Digital TDS-3 or better yet the COM-100 which is the only hobbyist grade TDS meter that will read in tenths and can be calibrated in three different modes including electrical conductivity.

sarajo, what is the TDS directly out of the RO/DI unit? Phosphate meters do not work well on RO/DI or ultrapure water since there are so few ions present. Its tough to get any sort of accuracy except electrical conductivity or TDS.

 

[sarajo]

0 coming out of the unit after I changed the filters, but it was zero coming out of the unit a few days ago before I changed the filters and I'm using the tds-3 HM

 

[AZDesertRat]

Prefilters and carbons have nothing to do with TDS, they are there to protect the membrane and DI which do remove the TDS. The prefilter and carbon remove things in the visible to say 1 or 0.5 micron range, way bigger than TDS which is in the 0.0001 micron range. Some carbons do contain traces of phosphates but the membrane and DI should capture those if you did not flush the filters when you installed them which I hope you did?

 

[sarajo]

i flush the unit using the fast flush contol knob everytime i use it

 

[sarajo]

Its reading zero tds but it also reads .02 to .03 phosphate. wierd makes you wonder if any tests are accurate, and maybe should just go by the looks of the tank. everything looks good in my tank just can't get the blues in my corals to come out and thought it might be phosphate but who knows.

 

[Sasquatch]

how about...
All reaction times are referred to as 20degreesC (68 degreesF). As a general rule of thumb, they should be doubled at 10degreesC (50degreesF) and halved at 30degreesC (86degreesF).

All reaction times are referred to as 20°C (68°F). As a general rule of thumb, they should be doubled at 10°C (50°F) and halved at 30°C (86°F).