testing phytoplankton

[Westeri]

I am growing phytoplankton to feed to filter feeders and copepods.   I am considering testing my phytoplankton to see how much leftover nutrients are in it. Since the culture medium is dense and would interfere with color identification  I wonder about treating it like testing for high level nitrate/phosphates.

For my test kit (for Nitrate), that would mean 15 ml of RO/DI with 1 ml of phytoplankton.   Any opinions or knowledge of whether that would allow an accurate measurement?

Just thinking I might be able to better tune the amount of nutrients I give a batch so I may minimize how much extra nutrients I add to system.   Or am concerning myself with something that will have too little impact on the system to worry about?

[AJ]

Well your other post said that you are adding 100mL per 250 gallons.  If you do the math, that is a minuscule amount.  Also, on top of that the amount of nutrients in the 100mL is not that high either.  I wouldnt worry too much about it. 

For the dosing, I dose a little bit every couple of weeks.  I store mine in some old water bottles and do not measure it out.  I have not seen any adverse effects.

[lazylivin]

Let your phyto settle to bottom over a day. Carefully pick it up and dump off 100% of the water. Then refill with fresh clean saltwater. This way you are only dosing phyto not leftover nutrients. You can change the water every month as well. I would concentrate 5 gallons of phyto that was so dense light couldn't pentrate down to a couple ounces  and refrigerate.. Then dose drops each day.

[Boonjob]

Let your phyto settle to bottom over a day. Carefully pick it up and dump off 100% of the water. Then refill with fresh clean saltwater. This way you are only dosing phyto not leftover nutrients. You can change the water every month as well. I would concentrate 5 gallons of phyto that was so dense light couldn't pentrate down to a couple ounces and refrigerate. Then dose drops each day.

+1 I did the same as Brian... I would half my gallon jugs with fresh water and I always grew it to the point where you couldn't see through it before splitting the batch.

I would split mine into old water bottles

[Twizted1]

Let your phyto settle to bottom over a day. Carefully pick it up and dump off 100% of the water. Then refill with fresh clean saltwater. This way you are only dosing phyto not leftover nutrients. You can change the water every month as well. I would concentrate 5 gallons of phyto that was so dense light couldn't pentrate down to a couple ounces  and refrigerate.. Then dose drops each day.

I agree, then once you have a stock in the frig. Let me know and I will purchase a bottle. 

[Westeri]

I just might.  Right now though I think it is going to require much more than a single day for the phyto to settle and I wonder if the motile phyto ever will.

[lazylivin]

Their shouldn't be any motile algae's in your culture. Regardless you only want what has settled over 24 hours. Everything above it is stuff you don't want in your reef such unabsored phosphorus

[Westeri]

So do you end up throwing out green tinted water or is it clear liquid for you?

[Boonjob]

So do you end up throwing out green tinted water or is it clear liquid for you?

Mine was always tinted which was the reason for my comment that my skimmed(part thrown out) was darker(denser) than most commercial products that were being marketed


This may help you understand the density we are referring to. The pic was the post skimmed, and split product.

http://www.ohioreef.com/index.php?topic=14843.msg130954#msg130954

[Westeri]

That is definitely darker than what was produced from my first 1 week batch.  Also darker than my new batch that is approaching two weeks of age.  Though this new batch is darker than the first.  It seems as if I may want to let it go yet another week.

[lazylivin]

Here is some information for you. https://docs.google.com/document/d/1-GrxkH09u50mM8uDCHbvYsOS0wlu4cnt8tFmxhDzX1U/mobilebasic?pli=1