Salifert Tests

[JoshsReef]

I just recieved from the doctors both a phospate and a nitrate test kit. First of all both my rodi water and my tank show 0 phosphates. (not sure if im testing correctly) is 0 phospates normal in a sw tank ? As far as the test is concerned it seems like with the phosphate test that the powder never really dissolves just kinda sits at the bottom of the testing vial, if anybody uses this paticular test kit is that normal?

My Rodi water tested at 25 ppm nitrate and my tank tested at over 100 ppm, I kinda wonder if im doing something wrong as I dont know what could be causing this in source water of 0 tds. Could something contaminate as it sits in a garbadge can? I am not sure who elses uses the paticular tests but I was kinda wondering if I could get some feedback on them to make sure Im doing them right. They arent like the cheaper test kits where all you do is a set number of drips of different solutions. It seems like how much of the powder is actually a level compressed scoop is pretty subjective, I dunno thats why I am asking, lol

 

[Kurt_Nelson]

Phosphate test - yeah... I normally have a little (not a lot) of crystals left in the bottom after swirling for 30 seconds, or whatever they say. My tank is normally 0. My DI water is normally 0. I know the test works though, because when I first got it my quarantine tank had phosphates in it (chemically treated shrimp that I used to cycle it... grrrr.....) and it turned blue like it was supposed to.

Nitrate test - I agree... the "compressed scoop" is kind of subjective. But I've played with it a little with the same water sample and used a "full" scoop on one test and a "not so full" scoop in another test. Same results. So I'm thinking it isn't that critical how full that scoop is... as long as it's full.

So are you saying that the water stored in your garbage can in 25ppm? Have you tested the water straight out of the RO/DI unit for nitrates? If it reads 0ppm, then yeah... I'd guess the culprit is your storage container. If it reads 25ppm, then obviously something is up with your RO membrane or your DI resin.

How are you reading the color chart? Remember... if you look through the top of the tube down, you read the color chart as it is printed. But if looking down you don't see any color and read through the side of the tube, you need to divide the numbers on the color chart by 10. So if you're reading through the side of the tube, and seeing 25ppm on your color chart, that's actually 2.5ppm. Make sense?

 

[Dave66]

The problem with hobby-level phosphate tests is they don't read down to NSW levels of 0.01-0.02, thus your kits give you a reading of 0 simply because that's as far down as they can go, so it ain't necessarily true that you have no phosphate in your tank. Even .05 phosphate can help cause a nuisance algae outbreak.
Only reagent-based test kit I know of that reads down to NSW phosphate levels is made by Merck. I did a bit of searching for it before I posted, so I don't know if its even made anymore.
LaMotte makes a low-range phosphate reagent that gets close, down to .03, but both the reagent and the colometer to read the results are far from cheap. You wouldn't get much change from $1000 US for the pair.
You should buy a backflush kit for your RO/DI unit. They are inexpensive, around 20 dollars. The nitrate coming out is the result of nitrafying bacteria within your unit that have taken up residence on your membrane. You obviously have chloramine in your tap water. The RO takes out the chlorine, and then there's ammonia. You're seeing the bacteria at work when you see that nitrate.
You should backflush every month or six weeks, depending on how hard your tap water is. Very hard do it sooner, very soft do it later.
Backflushing will solve your 25 ppm nitrate problem, and extend the life of your membrane markedly, as in several years before needing replacement.
Did you wash out the inside of your trash cans with soap and water? Reason I ask if you're having contamination in it, it's most likely the mold release agents precipitating into the water. All those cans are molded, and there are agents which allow the molded can to pop out of the mold. Those agents don't matter if your use the cans for trash, they do if you put tank water in them.

Dave

 

[cmor1701d]

That's the reason I only use BRUTE trash cans for aquarium use. All RubberMaid 'BRUTE" containers are food grade.

The maker of my RODI unit recommends flushing the membrane for a couple of minutes before and after each use. I'm in year 4 and have not had to replace the membrane yet.

 

[Innovator]

Elos Aqua Test Kit - Phosphate (Saltwater Aquarium Supplies > Test Kits > Phosphate Kits )

 

[JoshsReef]

I was looking through the side of the tube so I assume i was reading 2.5 which i still dont want but is a whole lot better than 25 and it explains why I had such a high reading in my tank as well. My water district uses chlorine, so I assume the small amount of nitrate came from the garbadge can. I wont have time to really tinker with these tests again till this weekend, hopefully I figure them out better.

 

[cmor1701d]

Yes, looking throug the side of the tube you divide by 10. That's what I have to do for my 'trates. The Ca, Mg and Alk tests are easier as there is a distinct color change as you titrate one drop at a time.

 

[Dave66]

Elos Aqua Test Kit - Phosphate (Saltwater Aquarium Supplies > Test Kits > Phosphate Kits )

Thanks for the find, Innovator . See that the price has gone up from the $75 per kit I used to pay. Bought it to corroborate the results from my Phosphate meter.

Dave