kien's 150g Room Divider Mixed Reef & Stuff

[kien]

You reminded me if one surprising result. When I tested my tap water for phosphates it came up zero!! Everyone is always freaked out about the phosphate content of tap water.. Why? I know that there is a lot of other junk in our tap water, hence my TDS reading of 214 but apparently phosphate is not among them. And yes I do realize that not all tap water is created equal.

Also, I am not surprised but I am disappointed that my nori had quite a bit of phosphate. Mainly because nori tends to not get consumed right away so there is plenty of time for it to leech it's phosphates unlike the other foods that typically get eaten immediately.

[fishytime]

Originally Posted by kien

You reminded me if one surprising result. When I tested my tap water for phosphates it came up zero!! Everyone is always freaked out about the phosphate content of tap water.. Why? I know that there is a lot of other junk in our tap water, hence my TDS reading of 214 but apparently phosphate is not among them. And yes I do realize that not all tap water is created equal.

Also, I am not surprised but I am disappointed that my nori had quite a bit of phosphate. Mainly because nori tends to not get consumed right away so there is plenty of time for it to leech it's phosphates unlike the other foods that typically get eaten immediately.

not much phosphate in our taps.....but test the water below the outflow of the treatment facilities on the Bow......its what makes the Bow the blue ribbon fishery that it is......phosphate grows weeds.....which grows bugs.....which grows trout

[Delphinus]

This is my understanding. Might be a bit oversimplified but as far as I know it's more or less correct still:

There is phosphates in everything, it's not going to be possible to get away from phosphates. It is like other things however, including NO3, in that there is some uptake by organisms so there will be some minor fluctuations in the levels from one day to the next however it is usually a given that we tend to input more than a tank is able to uptake and thus there is a residual value which usually creeps up in the absence of a PO4 reduction mechanism (eg. algae, refugium, ULNS, GFO, kalk, etc.) Some phosphate is necessary for growth, although too high a value inhibits calcification and thus inhibits coral growth or encourages tissue recession.

Anyhow that said, phosphate is not just phosphate, there is inorganic phosphate and organic phosphate. Of interest to us is organic phosphate, but you can only test for inorganic phosphate. Generally speaking we assume that the level of organic phosphate is around the same as inorganic phosphate, but that may not always be the case.

I remember reading that if you boil a water sample for some period of time and then test for phosphate, you will get a different value for before and after, because the organic phosphate denatures into inorganic during boiling.

Having said that however, that may not be the explanation for the tapwater producing a zero value. Drinking water standards dictate acceptable levels for many different parameters and AFAIK, nitrates and phosphates are to be zero (or very close to zero), and municipalities are thus mandated to provide water as such. I remember there was a big thing in the news about some small town had to provide bottled water because the tapwater had a detectable level of nitrate.

I could be wrong but that's what I always thought anyhow.

[kien]

Originally Posted by Delphinus

...
I could be wrong but that's what I always thought anyhow.

Cool thanks Tony!