Are my test results possible?

[crankbait09]

I am using Salifert test kits all the way across the board. I have been testing for Phosphates since December 18th, 2015. I have recently been hit with the brown algae that is now turning in to green hair algae. I know this is common for new tanks. To my understanding, this algae grows with phosphates in the water. With all the tests Iv'e done for phosphate, my parameters are at 0. My test water is always clear. No hint of blue anywhere. If I have this algae, with no phosphates detected, how can this be? Shouldn't I have some type of coloring?

If I have readings of zero after all this time, Leaves me wondering if my Ammonia is reading correctly. I have been at zero since November 29 when the cycle was completed. Every week I test the water, the test is ALWAYS zero. Again, is this accurately possible?

After all that, here are my tanks specs as well as latest parameters since this past Saturday:
130g DT, 40g Sump
Livestock: 2 percula clowns, 3 scarlet reef hermits, 2 cerith snails, 2 nassi snails

Ammonia: 0
Nitrite: 0
Nitrate: 20ish
Phosphate: 0
Calcium: 390
Alkalinity: 9.6
Magnesium: 1500
Salinity: 1.026
Ph: 8.1ish
Temperature: 78.3

[RayAllen3422]

My understanding is that your algae growth is using the phosphates to grow and grow. That is why they are showing as zero.

[Rubasu]

I think the tests are correct. I had the same issue with algae and phosphates reading 0. I was told that the algae is taking it in quickly, so your test may read 0. I think your ammonia, nitrite, etc are fine because otherwise your stock would be hurting / dead.

[crankbait09]

I think I also left some important information out. I do have 3 small soft coral frags in my tank as of last night. Not sure if those would effect anything right now.

I do have a GFO reactor, but it is not currently running.....

[TimeConsumer]

Pretty much what has already been stated. Your tank is going to go through several algae phases as the ecology balances itself out, especially if you started with a lot of dry rock. Diatoms, cyano, film, hair, dinos, bubble, etc.

I wouldn't worry about it too much. Maintain proper husbandry by not overfeeding, keeping up the water changes and siphon out detritus. Let your tank find its balance. If the problem persists you can look into running some GFO in a reactor to help combat the problem.

And another thing, phosphate tests are notoriously difficult to read. Many of use use the digital ones for that reason.

[crankbait09]

I thought about the digital ones, but i hear good and bad about them

[TimeConsumer]

Originally Posted by crankbait09

I thought about the digital ones, but i hear good and bad about them

I loved my Hannah checker. It took me some time to dial in my ritual for accurate results. But once I did it wasn't bad. On another note, I didn't really even test the tank water with it, mostly I just tested the output from the GFO reactor to determine if it was time for more GFO. I could tell if the tank had phosphate or not by just looking at it.

[crankbait09]

uh, what will you see just by looking at the tank?

[Reef Frog]

The chemical tests, even the good ones like Salifert, have a margin of error that makes a truly accurate reading on the low end quite difficult, if not impossible. They're best for detecting high & medium concentrations.

Also, PO4 is going to be in a higher concentration in the tiny layer of water surrounding your live rock, where the algae is growing, while in the water column it's so diluted it escaped detection. Some algae itself can also collect detritus and tiny invertebrates, so decomposition & waste production is happening right on the algae, feeding it.

[TimeConsumer]

Originally Posted by crankbait09

uh, what will you see just by looking at the tank?

More algae growth. Once your tank becomes settled and established you'll know what your baseline algae growth is. If more starts cropping up, that means your PO4 is higher than usual.