Help! My 3 day old terrarium already has mold :( - Orchid Board

DesignerofBeauty · #1 05-11-2018, 02:58 PM

Hello Everyone,

Thanks to the wealth of information found in this forum, I have built my very first orchid terrarium. I purchased all of the orchids and built the terrarium Tuesday. Already, one of the mounts has mold on it. I already used some tissue to remove the mold. In addition, I put a few drops of Physan 20 in a plastic cup and filled it with some water. I used a cotton ball and Q-Tip and applied the Physan to the areas where there was mold. Unfortunately I didn't photograph the mold. It was snow white and in circular patches.

Could someone please let me know what I'm doing wrong that caused the mold to appear in three days?

Here's some information on the setup: I have a 8inx8inx12 inch exo terra nano. It's a very very tiny enclosure. To construct the terrarium, I used the plastic egg crate lighting panels. The panel was cut to the size of the terrarium. I used Pond & Stone Great Stuff Foam and sprayed the panel. I trimmed the foam to make it look neat. I then used Aquarium Silicone and attached Hygrolon to the foam panel.

I bought a bunch of orchids from Andys. I removed the wire hanger. I secured each mount to place with a needle threaded with monofilament. I wrapped the monofilament around each mount a few times to secure it.

I have a false bottom. I used Exo Terra Bio Drain as a substrate. I put a Exo-Terra Bio Drain Mesh on top. On top of that I flattened Sphagnum moss to create additional protection. On top of that, I put ABG.

The terrarium's light source comes from a regular LED bulb you can get at any store. It's a 75W equivalent bulb that runs on 12W. The bulb is powered by a hood that Exo-Terra creates for the nano. When the hood is placed on the terrarium, there's a 1.5 inch gap which I assumed is plenty of air circulation. There's also venting on the front of the Exo-Terra, but it's covered by my ABG.

The terrarium's temperature ranges from 75-85 degrees. The hygrometer I've used says that the humidity is around 50%, but I've doubted that figure. I've used another hygrometer that reports higher humidity.

I use distilled water and a mister to spray the terrarium once the plants dry out slightly. All of my plants (with the exception of S. Fragrans) like to be kept moist but to dry out slightly. I've attached a few pictures to further help with my question.

Top Row (Left to Right): Schoenorchis Scolopendria, Stereochilus Brevirachis, Schoenorchis Fragrans, Dendrobium toressae, Mediocalcar Decoratum.

Middle: Gastrochilus Japonicus and Pleurothallis Leptotifolia

Floor: Dyakia Hendersoniana and Angraecum Distichum

The mold was present on the bottom edge of the S. Scolopendria mount (top left hand corner of the photo) where the edge of the mount meets the moss. I also found some on the back (where it touches the hygrolon).

I plan on getting a computer fan to help rectify the issue. My thoughts on why the mold developed: Maybe I need sprintails? Or maybe the hygrolon keeps the back of the mounts too moist, creating mold? Or maybe I've attached too much moss? If anyone has any advice, I'd greatly appreciate it!

Thanks for reading all of this

SaraJean · #2 05-11-2018, 04:27 PM

First things first, I do not grow in a terrarium. I really hope someone will jump in with more detailed help. I have been trying to plan out my own terrarium set up for about 6months.

Don’t plan on getting a computer fan. Get one now. Heck, drive down to the store today and get a little clip on desk fan to get some air moving in there. I don’t know terrariums but I do know humidity (I basically live in the swamp) and therefor I’m pretty familiar with mold and how fast it grows. I would think the mold developed due to the lack of air movement. I do think it’s best to have everything ready to go before you start putting orchids in a tank, but that time has passed so at least go get a fan. That is a very beautiful setup with some fantastic plants (I am useless on their specific care), but if some of your orchids die off in there, don’t replace them for sometime, at least until you get your tank culture figured out. I have seen that terrariums can be a little finicky in the beginning so I’m looking forward to reading what others can add.

EDIT: also, please someone correct me if I am wrong but while mold can be an indication that something in the culture is not quite right (like high humidity + plus low air movement, or maybe something is decaying) I didn’t think the mold itself was actually harmful to the orchids? I’m going to leave that one with a question mark..

Pattywack · #3 05-11-2018, 10:18 PM

I would like to add a suggestion if I may. I have an Exo Terra, it’s been a pleasure for two years. My tank is 12x12x18. I absolutely love it and I am now getting things together for a 8x8x8 nano tank. Even smaller than your tank.

Mold, as in white mold or could this have been algae? Many of these miniature orchids have algae on their mounts from the vendor. It has never been an issue for me. I have not had mold in my terrarium or any of my enclosures for that matter. I do use tiny fans in some enclosures but not in my Exo Terra.

The Exo Terra has pretty good ventilation built into the tank. It looks to me as if you have your plants mounted too close together, there is no space for air circulation between the mounts. I have three mounts on the top of the background in my tank, there is a least an inch between the mounts. These plants will grow, you need to give them space to accommodate growth as well as air circulation between. You have five mounts all almost touching each other.

I realize your nano tank is taller than the one I am currently working on, the footprint is the same and I’m looking to use three to five MICRO miniature plants in my tank, you have nine plants in there. At some point you may need to remove a couple to accommodate their growth.

If you choose to add a fan it should help but if it were me I would space those mounts out much more.

I do not have a false bottom, just LECA with forest moss on top. The background is the standard ugly Exo Terra, hacked down to about half the thickness. Mounts are hanging from that background, live moss is added/growing between the mounts.

The hygrolon could be keeping things pretty damp. I’ve not used it. I hope this has been a bit of help, maybe other terrarium nuts will add their opinions.

Looks good, keep working with it. These are a delight to grow and enjoy.

bjmac · #4 05-11-2018, 11:42 PM

If it is so you can uncover the exo terro vent it might help. I can not tell if your top is covered or not. I have mine covered, but with a 1 inch gap. I do not think that you should need a fan I do not have one on mine. My humidity has run as high as 90% and I have not had a problem, but I try to keep it around 70%. I have heard about mold growing in a new tank, but it will die off with time. If it is a small patch I would not worry. I have hygrolon over cork for my background with the hygrolon wicking water from the bottom of the tank under the false bottom. It should be damp to the touch, but I have not had a problem with it being to wet. Young tank take time to stabilize.

I looked back at the first picture and all the moisture on the glass has the humidity higher than you need it unless you just misted. That much moisture is probably around 90%. I have found that most plants will do better with a lower humidity than sometime recommend.

Paul · #5 05-12-2018, 12:14 AM

Quote:

Originally Posted by bjmac

I looked back at the first picture and all the moisture on the glass has the humidity higher than you need it unless you just misted. That much moisture is probably around 90%. I have found that most plants will do better with a lower humidity than sometime recommend.

That was my thought as well. If you just misted prior to the photo that is one thing, but otherwise that much moisture in the form of condensation indicates too much moisture may be your issue. A little PC fan would not hurt should you choose to go that route

DesignerofBeauty · #6 05-12-2018, 11:25 PM

Thank you so much everyone! Sorry I couldn't get back to you sooner, I had my mother over today for mother's day (a day early). I will probably have to remove some orchids to allow for more air flow.

Regarding the humidity/water around the sides of the tank: I did take this picture immediately after misting my plants. The water droplets usually evaporate within an hour.

Even though a fan might not be needed, one is one the way. I figure it can't hurt.

Hopefully as bjmac stated, this is just the terrarium adapting to the new conditions. I hope the mold doesn't reappear.

Does anyone here use springtails? I'm kind of grossed out by the idea. However, if it helps these things from happening, I'd be willing to try it out.

Ray · #7 05-13-2018, 07:40 AM

OK, this is going to sound like a sales pitch, but it's really not, but just a thought that jumped into my mind while waking up...

Consider spraying the thing with Inocucor Garden Solution. It is a blend of about a dozen or so beneficial bacteria and fungi that predate pathogenic microorganisms, so it can't hurt.

I don't know of anyone currently doing this in terrariums, but the live microorganisms populate the environment and the plants themselves, stimulating growth, absorbing and converting otherwise unavailable nutrients into usable compounds, and transferring them directly into the plants. Their metabolic byproducts also include sugars, proteins and amino acids that would naturally come from native microflora and -fauna in the wild. They also “beef up” the plants’ natural defensive capabilities as well as predating pathogens directly, resulting in plants that are relatively unstressed by diseases.

estación seca · #8 05-13-2018, 02:20 PM

I don't see any mold in your photos. The remaining plants look very healthy. How much mold was there? Are we talking a spot the size of a match head? A dime?

White mold in enclosed spaces is usually a saporophyte (that is, it grows only on dead material.) It will not invade your living plants. If you remove the dead material the mold has nothing on which to feed. I ignore white mold on the few mounts I have inside jars.

I think there's a real possibility you have no problem at all. You certainly do need some air circulation, but a little mold on a dead leaf from time to time is nothing to worry about.

The Dyackia really does need very high humidity, by the way. I would keep it near the bottom of the terrarium.

DesignerofBeauty · #9 05-15-2018, 08:20 PM

Quote:

Originally Posted by estación seca

I don't see any mold in your photos. The remaining plants look very healthy. How much mold was there? Are we talking a spot the size of a match head? A dime?

White mold in enclosed spaces is usually a saporophyte (that is, it grows only on dead material.) It will not invade your living plants. If you remove the dead material the mold has nothing on which to feed. I ignore white mold on the few mounts I have inside jars.

Estacion, it was about a dime sized with a few match head sized spots. Good to know that the mold is harmless.

estación seca · #10 05-15-2018, 10:36 PM

White fuzzy mold growing on dead plant material is usually harmless. It is often a sign the humidity is too high, there is not enough air circulation or the grower is not removing dead leaves and stems fast enough.

Fungus singular / fungi plural grow in microcopic, long tubular structures called hyphae, made up of cells attached end to end.

Some fungi grow their hyphae on dead matter. They break down the dead matter and use the nutrients to grow. These are called saporophytes, or saporophytic fungi. A large collection of hyphae may become visible to the eye. This is called mycelium. This is the fuzzy white fungus you are seeing. If you see mycelium on a living plant, it is rarely invading the plant; it is growing on the surface, or growing on a part you didn't realize is dead. This happens a lot on dead roots.

Some fungi grow inside living organisms. These usually cause trouble. They may grow in air or fluid spaces, like our sinuses or bladders, or they may invade actual cells. Those invading cells are said to grow endocellularly. Hyphae invading cells are not visible to the eye without a microscope. Spores enter leaves via open stomata or cuts. Some grow mostly on the outside of the plant, like powdery mildew, and penetrate shallowly. Others grow entirely inside the plant.

When it is time to reproduce, fungi form specialized structures to make spores. These spore-forming structures are called fruiting bodies. The mushrooms we see in the forest, on lawns and in markets are fruiting bodies. Spores are designed to be spread by the wind, so they need to be released to the air. Many people think the fruiting body is the fungus, but it is usually a very small part of the whole organism. Most, but not all, mushrooms are fruiting bodies of saporophytes. If you tear up dead logs in a moist forest you will often find threadlike mycelium inside the dead wood. This produces mushrooms (fruiting bodies) when conditions are correct.

Endocellular fungi grow fruiting bodies out from the plants they invade, into the air. You may have tried rooting woody cuttings in a pot with a glass jar inverted over the cuttings. If it is too warm and humid inside, tiny stalked black fruiting bodies will emerge from the rotting tips of the cuttings. Some orchids infested by fungi develop bumps or spots where spores are being released.

The treatment for saporophytic fungi is to improve growing conditions: control humidity to a desirable range, provide adequate air circulation, remove dead plant material promptly.

The treatment for fungus inside the leaves is staged: better, prevention; less good, amputation; even less good, chemical.

Give plants adequate light, air circulation to leaves and roots, proper water and ambient temperatures, and good but not excessive humidity. Healthy plants are far less susceptible to fungi (and bacteria.) Some of the commonest ways orchids become fungus-infested include keeping Phals too cold; keeping any orchid too warm, too humid, or poorly lit; or suffocating the roots. Tightly closed terraria with poor air circulation are famous for developing galloping fungus infestations.

Keeping growing areas clean gets rid of fungus spores. Washing down growing surfaces, and cleaning containers and tools, with 10% bleach solutions kills most spores. Many commercial growers do this on a regular basis.

If you do see diseased plants, separate them from the general population, and treat them quickly, before fruiting bodies form to release spores. Isolate new plants for a while before deciding they are fungus-free.

Beneficial microorganisms can kill harmful ones. This is the principle behind Inocucor and other rhizobacterial supplements. They have been shown to decrease incidence of fungus infection in many situations. People here on Orchid Board report good results with some of these products. If I had terraria I would use Inocucor on them monthly, as Ray recommends.

If prevention didn't work, try cutting off the infected plant part. Sanitize the tool between cuts with 70% alcohol, 10% household bleach or fire. Or use single-blade razors for one cut each. Hyphae are often present in healthy-appearing tissue an inch / 25cm away from obviously diseased tissue. If you don't remove all the diseased cells the fungus will keep growing. Cut well back from the disease and inspect the cut end. If it looks clear - no brown, no black spots - dust just the cut with powdered cinnamon, which contains antifungal agents. Don't get cinnamon on roots; it can damage them. If you see rot after the first cut, keep cutting. Afterward keep an eye on the plant. If the fungus recurs, you will have to cut some more.

Hydrogen peroxide kills fungi, too, but it is converted to oxygen and water in seconds, so it's not useful treating cut surfaces. It also damages roots. Hydrogen peroxide is useful for crown rot in Phalaenopsis. Put a few drops just into the diseased crown. Let it sit for 10 minutes, then remove it.

Antifungal chemical agents kill fungi. They are toxic to you, too. I don't like to use them except as a last resort. Some are not absorbed by the plant, so they only kill fungi they touch. Others are systemic, taken up by the plant through the roots. Systemic fungicides are necessary for endocellular fungi.

Not every fungus is susceptible to every fungicide. If you use a fungicide on a fungus not sensitive to the fungicide, it will not work. This is why most people recommend figuring out what fungus you have before applying a fungicide.

Fungicides will kill most of your beneficial microorganisms, the same way Roundup kills many beneficial soil organisms. This renders your plants more susceptible to infection with other fungi in the future - another good reason for not using fungicides except as a last resort.

It is especially poor growing practice to substitute regular fungicide treatment for proper care. Some people live in places naturally too humid, or too cold for many orchids. In cold-winter areas it is difficult to provide adequate air circulation to a tightly-closed greenhouse, so humidity may be higher than desirable at a time of cool temperatures and low light. This can be a recipe for disaster, which is why many people try to keep their plants drier in winter.

It may be necessary to use fungicides more frequently if poor growing conditions cannot be avoided. But most of us aren't in this situation.