Reef Chemistry Question of the Day #30 Chemical Layering

[Randy Holmes-Farley]

You did answer my question. After reading "What Your Grandmother Never Told you About Lime", I started using it as a "purifier" or flocculant. I vacuum my sand bed and pull up a lot of that milky sludge. I use 1plastic baby spoon of Mrs Wages powder/5g of "dirty" tank water. I stir, don't shake, the cocktail, and let it sit overnight. The resulting clear liquid I draw off and use for certain cultures, and the remaining sludge I use for a phyto culture. The phyto responds very well and very quickly to the addition of that sludge. I was just curious if the precipitated phosphates would be released into the water column in a low phosphate condition (hungry phyto culture) thermodynamically or if the precipitates remained insoluble and unavailable in salinity of .03 - .04 and 60 - 85 degree temperatures.
So you gave me good news. I hadn't taken Mg into consideration, either. Can I assume that the sludge is replenishing whatever is lacking very quickly in my very dynamic cultures regardless of temperature and salinity?

Oh, that's an interesting use that I hadn't really considered for adding solid calcium hydroxide to used tank water.

You likely do precipitate some calcium phosphate, and some phosphate onto precipitated calcium carbonate.

Some of it, on the surface of CaCO3 or pure chunks of calcium phosphate (if that happens), can redissolve if phosphate gets low enough. Phosphate deeper in the CaCO3 particles won't be released unless the whole particle dissolves.

The sludge likely does contain a lot of magnesium.

But I'm not sure how much of what is being delivered to the cultures.

 

[yarddoctor123]

I'm curious. Is there a better method to test all these parts of the water and sludges before and after the addition of calcium hydroxide? Or should I just be happy with the results I get? haha

 

[yarddoctor123]

Maybe I should test the phyto water immediately after adding the sludge and then again one day later?

 

[Randy Holmes-Farley]

Maybe I should test the phyto water immediately after adding the sludge and then again one day later?

What things are you most interested in monitoring?

 

[yarddoctor123]

Ca,Mg, Sr,

 

[yarddoctor123]

sorry hit the wrong button. Potassium and iron, too.

 

[Randy Holmes-Farley]

I doubt you can measure the iron, since it should be way below the detectable level anyway (at least with a kit).

Monitoring calcium and magnesium (and alkalinity) additions might be interesting. Strontium less so, but maybe interesting.

I doubt it brings in any potassium.

 

[yarddoctor123]

So I don't hi jack this one, I'm going to start a new .thread. I will use the MSHM ... mad scientist home method. Lol

 

[Randy Holmes-Farley]

OK, we like mad scientists!

Happy Reefing.