Had a great time at the WAMAS Spring meeting today. Picked up a nice little branching Frogspawn at the frag swap. It also has a little green tube worm attached.
Julian was quite a nice guy and of course very knowledgeable. He spoke about "Old tank Syndrome". I believe he covers this topic in volume III of his book
The Reef Aquarium. Here are some of the highlights:
Old tank syndrome is a multifaceted phenomena that occurs as tanks age manifesting is some or all of the folowing:
Decreased growth rate of corals
Decrease in coral health
Change from coral dominated tank to algae dominated
Change in diverse algal community to bare pavement
Loss of coralline algae
Decline in fish carrying capacity
1. As fish increase in size, food intake rises resulting in DOC and POC
accumulation.
2. See more Head/lateral line erosion due to malnutrition. Not
feeding enough (He said he likes to feed his tanks heavily).
Increase in nitrates
Increase in phosphate
Decrease in minimal oxygen levels
Decrease in pH
Decrease in alkalinity
Decrease in Magnesium
Change in ionic composition in water chemistry
Some of the theories why old tank syndrome occurs were:
1. Xenobiotics and alleopathy-Buildup of chemical substances that are
foreign as well as naturally occuring compounds, ie those produced
by chemical warfare of corals and growth domination by one type of
coral. We counter this with protein skimming and the use of carbon.
2. Reduction in flow
a. Return tube and drain tube clogging with calcareous organisms,
calcium and magnesium carbonate. Decreases tubes inner
diameter.
b. Clogging of pumps by much of the above.
c. Decreased efficency of PH impellers due to buildups.
d. As corals grow they block flow.
3. Reduction of pore and pore space of substrate.
a. Sand filtering/bio filtering occurs largely by advection and partly
by diffusion. His theory is that as detritus builds in the substrate
there is a decrease in oxygen saturation, a decrese in
nitrification and a decrease in porosity of the individual grains
of sand.
b. LR on sandbed increases advection, which is good, but also
adds to the detritus.
c. Solidification of sand bed over time decreases advection. It's
caused by the high alk and ca levels we keep our reefs as well
as bacterial biofilms and it's hard to prevent. Thus sand sifting
and burrowing organisms to help keep it from solidifying.
d. He said he saw no reason to change the substrate or LR over
time. He recommended against vacuuming or changing the substrate. He said he doesn't vacuum the substrate in his tanks and may just stir-up one small area a month, if that. Apparently, diatom algal
blooms occur as a result of disturbing the substrate.
4. Loss of clean-up crew over time.
a. May need to add more sand sifters over time as they die to keep
the sand clean and porous.
5. Build-up of heavy metals.
a. According to Julian, this is a controversial subject, but in his
opinion it doesn't seem to be problem.
6. His "IT" theory.
a. Is when a certain species of coral stops growing after a long
period of healthy growth. There's decreased health, necrosis
and extinction in the tank. The tank becomes immune to that
coral. Even a frag that was given to someone else would
not grow in the "IT" tank if returned.
b. It's caused by
1) Water chemistry
2) Parasites (Red acro bugsa and flatworms) Most likely
cause in his opinion. Recently advances have been made
in identifying protazoans that are killing Elegans corals using
a microscope. If you have an Elegans coral that sends out
mesenthelia tissue then curls on the end, it has this
protozoan.
3) Bacteria "Toxic Tank Syndrome"-When bacterial blooms
release harmful chemicals, kills everything.
4) Alleloplathy/Xenobiotics
5) Viruses-Bacteriophages. May be the cause of the loss of
good bacteria as they are infected with viruses. With the
loss of good bacteria colonies of corals are affected and die.
Here is picture of me (on the left) and Julian at the meeting!
Julian had a great way to affix corals to the LR. Take a wad of epoxy and press it into the LR. Then press the end of the coral into the epoxy and remove to leave a mold of the coral end. Let the epoxy dry 20-30 minutes until it hardens then glue the coral into the molded piece of epoxy with Corafix (cyanoacrylate). I also won a Euro Reef protein skimmer in the raffle and got a free sample of Two Little Fishies new Coraffix coral glue at the meeting. All in all it was a great meeting and I learned a tremendous amount. I highly recommend listening to Julian speak if you get a chance!
