Copepod Scrubber

Another strange project. I've grown copepods on and off now from the year dot, always using some sort of micro algae, nanno etc. I have now managed to raise a bunch of copepods using D&D SPS food (powder), and they look very healthy obviously with the obligatory waterchanges. This project is basically an attempt to increase pod production through filtering the water using a small horizontal scrubber, lit from above, circulated by the inherent bubble system of a bubble lamp (modified to flow over an angled plate hopefully pulsing the growth area). Could be an epic fail but I'm going to give it a go

 

Don't now why but having trouble with the vid.

Seems to work if you copy and paste "http://youtu.be/0Pe75ik5XWw" into a browser

 

Screen and pods been in for 4 days now. Screen was a well scrubbed (back to white in freshwater) used section of the original badass surge tank screen;



And just for the hell of it, I used a bit of badass algae (again washed in freshwater) to re-seed the screen. I left the tiny bit of free floating algae in there, and it's grown well. I may have made a Filamentous Algae Bioreactor

 

Cinematic gold 2 weeks (ish) ;

 

That's a lot of pods. When are you going to harvest some? Or have you already?

 

Going to harvest when I clean the screen. I've noticed that when I turn the airflow off, the pods migrate to the top and hover around the GHA. I'm hoping that as I pull the screen out, a goodly amount will be trapped on the algae mat. Then a quick rinse in the display before harvesting the screen, so I may be able to control the harvest amount. I'm guessing the first harvest will be in about a week or so. I'm feeding daily (1/2 of one of the tiny spoons you get with the SPS food). Nitrate is currently at <0.25, waiting for another phos test kit before I can measure P.

 

Good news, the pods are multiplying like crazy
The usually build up of pod poo on the culture base is barely noticable and much cleaner than the static culture I've also got going.

Bad news, everything else

For starters, the algae on the screen almost stopped growing, and became very "fluffy" or "thin" in cross section, just like it had ran out of food.

Tested the phos at 4ppm

Most of the algae was not attached to the screen, with perhaps 80% bare

Added a bit of iron and powdered spirulina, to see if other elements may be growth limiting. The initial makeup water was new saltwater (RODI/instant ocean) with a filtered pod culture.

 

Supposed to grow enough algae to maintain water in good "pod reproductive conditions". Obviously not going to plan in that regard but if I can find out why, then there may be things to learn from it or maybe not. I don't think the pods are eating the screen algae because I'm pretty sure they are filter feeders.

 

Might as well just set up a little tank with a conventional scrubber and scoop some out with a net now & then in that case.

 

I don't give up that easily

 

Update - no extra growth so dimmed the lights for a while, still nothing. Did a100% water change (obviously trace amount of nutrient from the pod sieving) and now it's growing again. It seems at present that the elevated nutrients were actually inhibiting growth, but open to suggestions.

 

Is it possible that as the biomass of the pod population increases, it overcomes the filtering capacity of the algae growth area available?

Or that pods produce something that can't be efficiently filtered by algae & which limits it's growth?

 

Well, it seems nothin related to the pods. Perhaps it was a temperature/acclimatisation thing (now at 15 ish degrees, previously 26c) either way, it's growing now. A picture of the tiny screen (4inch diameter) after releasing the pods into the display.

 

This is still growing. I've cut down the feeding to half of a tiny spoon full of SPS food a week;

I'll do some N & P tests later

 

Is it worth the effort though in your opinion?

Are you getting enough pods from it?