What is Biofilm?

[Neo-shrimp]

Thanks njslocksmith :stupid:

I'm no fishmosy but I think I can answer your question : ial = Indian almond leaves

[fishmosy]

The main species I work with is a sea urchin called Tripneustes gratilla (common name lamington urchin) but I also work with another six species of sea urchins, and a couple of species of star fish including the Crown of Thorns starfish (COTS). All of these guys spawn into the water column. The resulting larvae swim around for at least a week, (most of them closer to ten weeks, and some have been kept in culture for almost a year) before settling onto the bottom to take on the adult shape. Soon after settlement they begin feeding on biofilm before moving onto adult foods once they get a bit bigger.

I haven't done anything with abalone as I consider them to be a bit of a waste of time. For example we believe that we can get T.gratilla from larvae to harvestable size in 6-9months, whereas it takes 2-4years to grow abalone to a saleable size. I mention abalone though because the techniques used to grow abalone were adapted for sea urchins in around the 1980s and their lifecycles are similar.

The reason why we want to grow sea urchins is because the gonads (known as uni) are eaten by people, principally the Japanese market. I've seen the gonads of T.gratilla sell at $500-1000AU per kilogram of gonad, or roughly equivalent to $8-15 per urchin, but averages $500-700AU per kilo, however this is still far in excess of any other sea urchin which usually get less than $100AU per kilo. T. gratilla is also seen as a bit of a status symbol in Japan and is reportedly the best tasting urchin there is. Fisheries collapses for T. gratilla means the only way to supply the increasing demand for these guys is aquaculture.

Edited August 6, 2017 by fishmosy

[BlueBolts]

Thanks fishmosy....you've got my vote for having the best job around !

[fishmosy]

Technically I'm still a student as I'm finishing off my PhD, less than 12 months to go now. I'm on two scholarships so I count it as work.

[northboy]

Thanks Mate, I will now put one or two of those tanks after the Sump filter in side for Bio film and one out side in the sun light to grow Algae.

Ask the Doctor it works, thanks Dr Mosy, you do realise I will call on you for tech info in the breeding projects because you explain in ENGLISH.

Bob

[BlueBolts]

Yes, fishmosy, this is inspirational....my outdoor pond is now going to be my Biofilm factory !

[fishmosy]

Just be careful how you do things when growing biofilm. Remember to cover your ponds/containers/tanks to prevent nasty bugs getting in. Be mindful too that pest snails will also love to snack on your biofilm so prevent them getting in to stop you ending up with a bunch of snails and little biofilm.

[northboy]

I will be going to anal lengths to keep out unwanted snails because I want the Bio for Neritinas.

Bob

[Gbang]

fishmosy, thank you for such a great explanation and pics. i've learnt a lot today from you. in your case uni was certainly not a waste of time!!! especially for all of us lol. mate can you please show me how the biofilm plate for the placos is made? it's genius!!! i've given you a reputation point but i reckon you deserve way more than one!!! *COUGH*GIVE HIM POINTS PPEPS*COUGH*

[fishmosy]

Thanks Gbang, I will grab some pics tonight, however after using the pleco plates for some time now I would do things differently. The major problem I alluded to was the cracks in the plates (essentially stress fractures) that I suspect eventually will cause the plates to come away from the rods, i.e. basically fall apart. The other reason is cost, the bits and pieces are not cheap in comparison the the PVC pipe we use for the large plates so I'm sure there is a cheaper solution.

I haven't really spent too much time thinking about what I will do next to try and solve this problem as I've been busy with other projects, particularly a tank I'm purpose building for zebra shrimp which will include a filter not used much in Aus, the humble hamburg mattenfilter. Thread to come on this so keep an eye out.

Necessity is the mother of invention so until the plates actually fall apart I probably won't do anything more on the plates.

[northboy]

Professor Mosy, keep an eye on Dump shops as you can pick up old perspex signs and pieces of perspex and they will work well, it wont matter about different thicknesses just make the saw cuts bigger in some. I will be running with the stand type ones because I found a lot of good perspex both white and clear at the dump shop, I was using it to mount odd Drift wood on that wont stand at the angle you want, now I have another use for it.

Bob

[fishmosy]

I did think of using flat plastic sheets but waved plastic has greater surface area within the same volume. Same thing goes for thickness. I think sacrificing a bit of surface area for longevity could be a good idea for guys building new pleco plates.

Good tip Bob. Its difficult to find thin flat plastic that doesn't cost an arm and leg.

[northboy]

If I can find the roof sheating at a reasonable cost I will use it to.

Bob

[fishmosy]

I've put up how I made my pleco plates here.

 

 

Edited August 6, 2017 by fishmosy

[fish4fish3]

So the stress fractures were from drilling not a "use by date" scenario? If so what type of drill piece were you using as the design looks good. I have drilled heaps of it without a single fracture ( remember my IBC wet / dry filter? )

I know scientists aren't the best at building stuff ( i know first hand when you helped put my sons swing up a little back ward and inverted ) So can give you a few hints and tips in building and construction.

[fish4fish3]

Also another note that may enhance a shrimps feeding ability on the plates may be to use a 40 - 60 grit paper and scratch the surface... this will also effectively raise surface area as well as give the shrimp an appropriate surface to feed off.

Like all my projects, Just a thought... I'm super old school and "do" let the practical work out the theory. If that makes sense.

[fish4fish3]

So which hamburg matten style? The first is really cool as used like a divider and the second will make good for a "Xmas" moss wall LOL

Edited August 6, 2017 by fishmosy

[fishmosy]

So the stress fractures were from drilling not a "use by date" scenario? If so what type of drill piece were you using as the design looks good. I have drilled heaps of it without a single fracture ( remember my IBC wet / dry filter? )

I know scientists aren't the best at building stuff ( i know first hand when you helped put my sons swing up a little back ward and inverted ) So can give you a few hints and tips in building and construction.

Haha, the cracks only occur because the ends of the nylon spacers are flat and the polycarbonate is curved, so it eventually cracks (months later).

[fishmosy]

So which hamburg matten style? The first is really cool as used like a divider and the second will make good for a "Xmas" moss wall LOL

it'll be the second one. I don't count the first pic as a true mattenfilter, the foam is primarily used as dividers, not filtration.

[fish4fish3]

Then don't tighten it so much... What you think the pleco's are going to steal them? Or get a soft / foam / sponge / rounded spacers or add the rubber gromets from roofing screws to them.

Edited August 6, 2017 by fishmosy

[Squiggle]

Unbelievable thread Fishmosy, you are a genius at the layman explanation. :encouragement:

Haha, the cracks only occur because the ends of the nylon spacers are flat and the polycarbonate is curved, so it eventually cracks (months later).

Just a thought, how about making some angled spacers or using rubber tubing :)

[fishmosy]

Thanks, that is the direction I will probably go unless I swap to flat plates. They haven't fallen apart yet so I'm in no rush, and I have plenty of other projects so this low on the priority list.

Edited August 6, 2017 by fishmosy

[Shrimpmaster]

Be aware that it takes time for the biofilm to grow to the thick brown layer in the pics, a week if heavily fertilised, several if not.

@fishmosy What specific fertilizer are you talking about?

[fishmosy]

@fishmosy What specific fertilizer are you talking about?

You can use pretty much any fertiliser you like. The point is to get some nutrients into the water to encourage algae to grow. For example I have used Yates Thrive dry powder general garden plant fertiliser with great success in the past. 

[Shrimpmaster]

One more question about biofilm. I believe too this is a very important food source for shrimplets. How do you explain that I was able to breed a whole lot of offspring in a new setup for quite some times. My best results were in a new tank that has cycled for about 4 to 6 weeks. Could it be that the biofilm was already good at the point the shrimplets were born (8-10 weeks after the aquarium startup) ? And could this also be why in very crowded tanks, the shrimplet survival rate gets lower, because all the adult shrimp eat all the biofilm?