Aquaponics 22: Damping off problem and solution

Hello all,
So, as the problem of my 'depressed' plants continues I sought help at one of the best forums for all things aquaponic (Backyard Aquaponics). And lo and behold, one of the nice chaps there might have identified the problem.
It seems that the issue is caused by something called "Damping off". This disease causes plants to look fine one day and the next they will be depressingly sad. Their stalk will wilt away and the plant will drop or fall over. Exactly what I've been experiencing.

Damping off - Aquaponic plants looking fine 

One day the plants will look great...

Damping off - Aquaponic plant in a sorry state, but look at those roots!

And the next they will have turned into the above example of a very sorry state of being.

So, searching the internet I've read a lot about this disease. It appears to be a umbrella term for the horticultural disease or condition caused by a range of fungi.

I've narrowed my type of evil attacker down to either Rhizoctonia solani or Pythium spp:

Rhizoctonia root rot (Rhizoctonia solani) is a fungal disease which causes damping-off of seedlings and foot rot of cuttings.  Infection occurs in warm to hot temperatures and moderate moisture levels.  The fungi is found in all natural soils and can survive indefinitely.  Infected plants often have slightly sunken lesions on the stem at or below the soil line.  Transfer of the fungi to the germination room or greenhouse is easily accomplished by using outdoor gardening tools inside or vice versa.  The germination room should not be used for mixing potting soils or transplanting seedlings as a general rule.
Pythium Root Rot (Pythium spp.) is similar to Rhizoctonia in that it causes damping-off of seedlings and foot rot of cuttings.  However, infection occurs in cool, wet, poorly-drained soils, and by overwatering.  Infection results in wet odorless rots.  When severe, the lower portion of the stem can become slimy and black.  Usually, the soft to slimy rotted outer portion of the root can be easily separated from the inner core.  Species of Pythium can survive for several years in soil and plant refuse. 
Source: http://tomclothier.hort.net/page13.html

Wikipedia has this on Rhizoctonia solani
"a plant pathogenic fungus with a wide host range and worldwide distribution. This plant pathogen was discovered more than 100 years ago. Rhizoctonia solani frequently exists as thread-like growth on plants or in culture, and is considered a soil-borne pathogen. Rhizoctonia solani is best known to cause various plant diseases such as collar rot, root rot, damping off and wire stem. Rhizoctonia solani attacks its host(s) when they are in their juvenile stages of development such as seeds and seedlings, which are typically found in the soil. It makes sense then this saphrophytic pathogen would live and survive in the soil, and attack the part of its hosts that reside there. The pathogen is known to cause serious plant losses by attacking primarily the roots and lower stems of plants and although it have a wide range of hosts, their main targets are herbaceous plants. Rhizoctonia Solani would be considered a basidiomycete fungus if the teleomorph stage is abundant. and is currently not known to produce any asexual (conidia) spores although it is considered to have an asexual life cycle. Occasionally, sexual spores (basidiospores) are produced on infected plants. The disease cycle of Rhizoctonia solani is important in regards to management and control of the pathogen."

 So, I've got a nasty (and rightly feared) fungus attacking my plants. And it thrives in wet, cold poorly drained climates - a perfect discription of my growbed at the moment :-(.

SOLUTIONS / TREATMENT
There seems to be a couple of solutions (even though any type of pesticide is out of the question!) that I can try:
1) Lower the Ph of the Growbed. Bacteria and fungus dislike low levels of Ph.

2) Only plant well established seedlings. This would mean setting up a heated nursery or similar, whereby the more developed plants would be less susceptible to Damping Off.

I'll give solution number 1 a try first, as it does not involve buying anything expensive. An old and well tested way of lowering the Ph is the application of chamomile tea. This has long been known to be useful against bacteria attacks, which is due to its PH lowering abilities.
So, my plan of attack is to sow a new batch of plants, apply chamomile tea daily and see what happens. If I can detect an improvement (which should be easy) I'll carry on with this approach, and if not I'll try and set up a small heated nursery for the seedlings.

Anyways, sorry for the wall of text :-).

All the best,
Kasper

Slime mold in the Aquarium

Hello all,
I recently told the story of my experiences with marine fungus growing on a Red Moore root. This reminded me of another crazy visitor to my fishtanks (I sound like an old sailor...).
When I initially set up the large aquarium, I saw something weird after a few weeks.

After searching the net hard and far, it turns out that this visitor was not an algae or similar (which I initially thought) but a type of marine slime mold.
Apparently these are something of a mystery to everyone, but shouldn't harm the aquarium in any way. 

 Now, unfortunately for the average non-marine biologist, information on these weird growths are very difficult to get hold of. But they are neither plants, mushrooms, or alage. Instead they are thir own little box, of unrelated but similar beings, halfway between fungi and snail-like creatures. The various types of slime molds can be seen here on this thourough German homepage: http://www.schleimpilz-liz.de/index.php?option=com_content&view=category&id=26&Itemid=48&lang=de (that states it describes 'Die fabelhafte Welt der Schleimpilze' :-)). Schleimpilze, I guess that translates into Slime-sausages....
Oh, and they move. Each morning the thing would have shifted across the aquarium to a new location. Quite fascinating!
I had, through a friend who is a marine biologist, set up a meeting with a Dane who happens to know something about these molds, but it took so long that the thing had disappeared by then. I have not seen it in over a year, and I fear it died or was sucked into the pump or something similar.

Shame, I would have loved to find out which type it was.

Slime molds are best known from the study that proved that a single species might have casued ill-effects on Eel Grass (i.e. "Labyrinthula sp., a marine slime mold producing the symptoms of wasting disease in eelgrass, Zostera marina", by Muehlstein, Porter, & Short), a study that is available online (http://link.springer.com/article/10.1007%2FBF00392553?LI=true).

According to their abstract they state that "Coastal ecosystems along the eastern United States are presently threatened by a recurrence of the wasting disease of eelgrass, Zostera marina L. Using Koch's postulates, a species of the marine slime mold, Labyrinthula, is identified as the causal microorganism of this disease. Our disease tests for pathogenicity performed on eelgrass, using four Labyrinthula spp., indicate only one species produces the disease symptoms identical to those found associated with the wasting disease. The pathogenic Labyrinthula sp. has morphological characteristics that distinguish it from the other three species. Identification of Labyrinthula spp. is difficult because species described in the literature are not clearly characterized or identifiable. Tests at various salinities demonstrate that disease symptoms appear infrequently at salinities of 10%. or less."

 Also these videos by Princeton's John Bonner show just how amazing slime molds are:

 Cool stuff!


All the best,
Kasper

White Growth on Red Moore roots? Causes and a quick fix

Hello all,
was just reminded of one of my first "wtf"-moments of keeping fish. I had bought an expensive piece of 'driftwood', called Red Moore roots (AKA Spiderwood) and was thoroughly enjoying it.

The root, seconds before the fungus attack .-)

And then this weird, white growth appeared and crawled all over my pretty decoration.
Nasty, I thought and began panicking.
Today I know better and would love to share this with all of you :-).

Causes:
Apparently whenever a root that has been boiled or similarly treated is inserted into an aquarium, a species of marine fungus will take this as their chance to prosper. And when they prosper, they grow large enoguh that we can see the resulting white fussy and fluffy growth.
And good luck searching for the scientific name of this species of fungus. Each type of wood has its own particular species of marine fungus. And as marine fungi are among the worst investigated lifeforms on Earth, theres quite a good chance we shall never know the name of the redmoore eating fungus.

Solution:
Well, this is the easy part. If you are not in a hurry, then just let it be. Once your aquarium gets better established the inherent bacteria will triumph. Growing much quicker than the fungus, they will soon conqour the spot and eat the easily available nutrients that the root is leaking.
If you are in a hurry (or find the growth disgusting), all shrimps love the fungus, and quite a few catfish (and other types of fish) will also eat the growth. So either way nothing bad will happen - either it will disappear on its own, or it will provide free food for your aquarium :-).

This qoute (from an old defunct homepage) sates the above in better English :-):
Floridadriftwood
About Fungus

Sometimes when an enthusiast brings driftwood home, the temptation to boil it before adding it to their aquarium becomes too great to ignore. When they do this, they sterilize the wood and leave it vulnerable to fungal colonization. If this happens, do not panic! Two things to note:

1. This fungus is harmless to both fish and plants. In fact, many fish will seek it out to eat it. Yes, it looks unplesant but boiling the driftwood again and again to get rid of it is futile. This just restarts the cycle of colonization.

2. This fungus is temporary. Once the natural bacteria in your aquarium have a chance to get a foothold, they will colonize the driftwood and out compete the fungus. The fungus will then seem to disappear; almost overnight.


All the best,
Kasper