Phosphate mystery

Forty-Two

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Hi all - I’m hoping to get some suggestions as to what may be going on with the Phosphates in my 30 gallon tank. The tank is young (~2 months old ) which could be the source of the answer - but to be sure I’m not lining myself up for a disaster - I thought it better to check.

TL;DR do diatoms consume phosphates?

The tank consists of 50% Live Rock and 50% Indonesian dry rock. There is also a sand bed about 1-1.5 inches in depth.

Parameter tests over the last few weeks have shown elevated levels of Phosphates - typically ~0.6 ppm. Nitrates are low at around 3 ppm.

In the tank for a couple of weeks was 2 clowns, 1xGSP and 1xFavia.

I did multiple large water changes (30-40%) for about 2 weeks (every other day I would say) to try to bring the Phosphate down. This didn’t seem to work as at the end I was still at about .6ppm. My guess was that it’s the dry rock leaching phosphates.

I added a couple more corals, and added a purple tang and dosed reef roids - this brought the phosphates to 1.36

I got some phosphate E and did dose it once - initially 5 ml - did a test and that brought it down to .2ppm. I dosed a further 2ml which brought it down to .03 ppm which I was satisfied with.

A couple of days later I’ve run my usual battery of tests and I’m seeing 0.00 Phoaphates. Nitrates are still very low at 1-3 ppm.

Ive also had a bit of explosion in diamtoms on my sand bed. I’m assuming this is consuming the phosphates? I’m feeding heavier on purpose but I’m wondering where the phosphates are now
 

Mr. Mojo Rising

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diatoms consume silicates, which normally comes from new sand that we first put in our tanks, it will die off on its own when the silicate food source is completely consumed, normally it doesn't last long, just a few weeks, then it will die on its own. No need to do anything about, and most certainly stop dosing things
 

BroccoliFarmer

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Hi all - I’m hoping to get some suggestions as to what may be going on with the Phosphates in my 30 gallon tank. The tank is young (~2 months old ) which could be the source of the answer - but to be sure I’m not lining myself up for a disaster - I thought it better to check.

TL;DR do diatoms consume phosphates?

The tank consists of 50% Live Rock and 50% Indonesian dry rock. There is also a sand bed about 1-1.5 inches in depth.

Parameter tests over the last few weeks have shown elevated levels of Phosphates - typically ~0.6 ppm. Nitrates are low at around 3 ppm.

In the tank for a couple of weeks was 2 clowns, 1xGSP and 1xFavia.

I did multiple large water changes (30-40%) for about 2 weeks (every other day I would say) to try to bring the Phosphate down. This didn’t seem to work as at the end I was still at about .6ppm. My guess was that it’s the dry rock leaching phosphates.

I added a couple more corals, and added a purple tang and dosed reef roids - this brought the phosphates to 1.36

I got some phosphate E and did dose it once - initially 5 ml - did a test and that brought it down to .2ppm. I dosed a further 2ml which brought it down to .03 ppm which I was satisfied with.

A couple of days later I’ve run my usual battery of tests and I’m seeing 0.00 Phoaphates. Nitrates are still very low at 1-3 ppm.

Ive also had a bit of explosion in diamtoms on my sand bed. I’m assuming this is consuming the phosphates? I’m feeding heavier on purpose but I’m wondering where the phosphates are now
Are you sure not dinos? Zero phosphates caused a huge Dino outbreak in my tank. You want some
 
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Forty-Two

Forty-Two

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Are you sure not dinos? Zero phosphates caused a huge Dino outbreak in my tank. You want some
Not 100% sure as I don’t have a microscope at this time to take a look - also I’m not we’ll versed in this area.

I suspect diatoms because they aren’t stringy. It’s like a red film. Interestingly enough it doesn’t scrape off easily from rocks. From sand it can be removed pretty fast however.
Also there appear to be small bubbles on the top and occasionally break off and float to the surface.

I did a 40% water change and dosed some phytoplankton (which I was doing previously but stopped) and now the phosphates are back at .26 for the time being. I’ll likely test again tomorrow and see where they are at.
 
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