Hi,

I'm new to this forum - need some help please.

I used to have some mushrooms growing in my terrarium and also some fuzzy white stuff which looked like fine spider webs (which apparently is some kind of moss). I started watering the plants less frequently and I got rid of these mushrooms etc but I am now encountering a new problem. In some areas around the terrarium, it's like the soil is turning white. The first time I threw away the soil which looked like this and moved around the remaining soil but after a couple of days, the same area started turning white again. Any idea what is this/what could be causing it please?

See attached image - A is the correct color - B is the white part.

Welcome to ATP, attardam.

Your images did not attach, could you try posting them again?

I am not familiar with terrariums, but I know climate can effect house plants in general. Please share your general location as this will help others give you an answer.

There are many knowledgeable people on the forum that will gladly help you. If they are away for the holiday, they will be back.

Welcome to All Things Plants, @attardam !

If you were seeing mushrooms and "fuzzy white stuff which looked like fine spider webs" (which I'm pretty sure was a type of mold, not moss), your terrarium was severely over-watered. Can you tell us a little bit more about your terrarium? Is it pretty much closed up, or is there a good-sized opening? (As Chillybean said, if you can try to re-post the pictures it would be helpful.) Another issue could be what type of plants are you trying to grow? Also, what sort of soil did you use? I've always used a layer of aquarium gravel, then a thin layer of activated charcoal, then a layer of potting soil for terrariums.

With the limited information that we have, my first thought is that your best course of action would be to completely start over (salvaging any plants that seem healthy), with new soil and a well-cleaned container. There are plenty of people on ATP with experience in planting terrariums, so I hope you will get lots of helpful answers here!

Hi Chillybean and Weedwhacker First of all, thanks for your replies.

Apologies for the image - I reuploaded it! I live in Malta (we have a Mediterranean climate). Sorry you are right about the fuzzy white stuff, I meant to write mold not moss!! Yes I think that that was the reason for the mushrooms etc - infact they stopped growing once we started watering them less frequently. The "terrarium" it is closed up apart from a small opening which is maybe 16 by 5 cms. It has light bulbs so it's a bit hot in it but we shower the plants every day with water. Tbh it is supposedly an aquarium, but for the time being we decided not to use it as one so we thought we would give it a try with plants. We have the area split into two - one side we have cactus while on the other side we have the plants seen in the attached image. Wrt soil we have a layer of substrate and then a layer of plantation soil I believe. The plants aren't dying or anything - they are actually growing really nice - but it's annoying to see this white "soil or dirt" and not knowing what's causing it.

Thanks once again for your help - much appreciated

Do you have a layer of charcoal in your tank? Have you checked out the miniature garden forum yet?
There is alot of useful information over there....
http://garden.org/forums/view/...

Are fertilizing with anything, or have a lot of minerals in the water? Fertilizer salts can form a white powder on soil surfaces.

@Christine: We have a layer of stones rather than charcoal. Thanks for the link - will check it out :)

@Sooby: We used to give them some miracle grow - we thought it might be it so we stopped watering with it. however we have this problem only at 2 specific areas in the terrarium. do you think that might be it?

Is there a chance that the fertilizer might puddle in the effected areas? I would go easy on fertilizer in a terrarium because excess salts won't get flushed through as they do in a pot, and also the plants most likely don't need very much anyway. Whether that's the problem is difficult to say without seeing it in person but it's a possibility.

Could be tbh - cause the soil is one of the areas where we have this problem goes a bit down compared to the rest of the terrarium. I stopped using it some months ago - will stick to not using it then. Do you that that I would need to change all the soil to get rid or will it get better by time?

You mentioned moving the soil around earlier, was that before or after you stopped using the Miracle Gro? I might be inclined to fill in the depression with new medium and see what happens. I don't know that I would change all the soil since the plants are doing well and we don't know for sure what the problem is. I'm assuming it is actually some kind of soilless medium and not actual garden soil (I'm not sure what "plantation soil" is)?

No after we stopped using the Miracle Grow - the first time this white stuff showed up, we removed the "damaged" soil and moved around the surrounding area to fill the gap. No it's not actual garden soil - we bought it from a terrarium shop. It comes in blocks then you leave it in water and it turns to soil. Thanks a lot for your help

If the blocks were coconut coir, some can contain excess salts but I believe it depends on the brand. Some require flushing before using. I don't know whether that is still commonly the case but it used to have that reputation. I've never used it so maybe someone else can comment if indeed it was coir. Another possibility is high mineral content water but I think that's a bit of a long shot. Also, might the blocks already contain fertilizer? Perhaps you could lift off a piece of medium with the white stuff intact and take it to the terrarium shop, since they'd be able to see it in person and would presumably have experience with terrarium growing? They might even have an EC meter that could check for excess salts.

That's a good idea - I will try and take it to the shop. The shop was more of a vivarium shop and the sales assistant did not seem to be knowledgeable about terrariums but maybe someone else encountered this problem with their vivarium. Thanks a lot for your help sooby much appreciated!!

I also thought "salt accumulation" when I read the text, but it did not look that bad in the photo.

Unless those are very salt-tolerant plants, their health suggests that it is NOT excess salt crystallizing on the surface!

But possibly there is some very insoluble mineral in the soil blocks or water that precipitates on the surface without high concentrations of sodium and chloride. (Do you use tap water? Do you have "hard water" with Calcium and Magnesium salts? If that was the problem, watering with rainwater or distilled water might help ... but how do you get salt out of a terrarium that has no drain?)

I could easily believe mold or fungus. It's humid and organic and the air sounds still. If it is mold or fungus, improved air circulation and reduced humidity might help. Take the lid off and run a fan? The remaining water will evaporate rapidly and make things look worse if it is salt, but maybe look better if it is mold or fungus.

Yes we do use tap water. What is confusing me is why this problem is only appearing in two specific areas around the terrarium. Tbh at first I thought it might be something in the soil of one of the new plants we bought but I don't know. The second area which has the same problem (apart that in the photo), is right around one of the last plants we put in the terrarium. If it's moss, wouldn't show all around the area where we have those kind of plants? I will try and take a cleaner picture when i get the chance. Thanks all

Well, if it is caused by water pooling, or evaporating selectively from certain areas, I would think that raising the low spots would help, by adding a little soil mix or scratching it around to level it. That MIGHT help either fungus or salts, by spreading the bad effect around evenly.

Increased air flow might help, if it is surface dampness causing mold or fungus.

>> we shower the plants every day with water.

If it is salts, maybe using bottled water, rain water or distilled water would prevent it from getting worse. Certainly "less fertilizer" will reduce salt loading.

>> this problem is only appearing in two specific areas

Just out of curiosity, what if you propped up the terrarium a few millimeters or 1/8 to 1/4 inch on one edge? That would make the opposite edge damper than the raised edge. If the low edge gets worse and the raised edge gets better, you would at least know that they want less water.

If the whitish spots stay right where they are, maybe it IS the plant or the soil right there that makes trouble.

I forget

Unfortunately it's quite bulky and it's on it's own base so it's difficult to elevate it from one side. We used to use dehumidifier water but changed to tap water recently. Will try bottled water now...

I was also thinking of replacing the soil of the whole area where we have this problem - we still have a block of plantation soil so thought of giving this a try. What do you guys think? You think it might help?

I looked up plantation soil and if it's the kind I found it is coco fibre as we suspected. If it's the problem then I wouldn't replace with that. You mentioned earlier there was another substrate underneath, do you know what that is?

The plantation soil I found is marketed for reptiles etc. but says you can use it for plants. I couldn't find anything about fertilizer etc. in perhaps because it's considered pet substrate and doesn't have any additives for plants.

Are any of the plants showing brown leaf tips or edges? If they're not and still seem to be OK I would prepare some of the coco in the same way as before, put it in a pot and enclose it in a clear plastic bag. Watch it for a few days and see if anything develops on the surface. If you're still misting or watering the terrarium then do the pot at the same time.

The bag of coco fibre should have a contact phone number on it, if it's toll free from where you are then I'd give them a call. Coco fibre/coir does have a reputation for salts but also can't rule out mold. A clearer picture might help. According to the manufacturer (if it's Ex-Terra) this stuff increases humidity for its animal occupants:
http://www.exo-terra.com/en/pr...

If you just want to go ahead and replace it without testing, I would go with something else formulated especially for plants.

Do you have problems with kettles etc. forming calcium with this water, so that you have to do a vinegar treatment every so often?

Yes that is the same exact plantation soil - infact I got it from that shop (which is infact a reptile shop) but the sales men all said that it is ok for plants as well. The substrate we bought it from the same shop too but I'm not sure which one since it's been over a year. What i'm finding strange is that we had this terrarium for over a year now but this seems to be a recent problem. Actually yes I do have 2 plants which have brown tips - one of them is the one which has this white stuff all around it. Any idea what causes this please? Yes we do have this calcium problem with tap water - so you think it's because of the water we are using? Thank you

I wonder how much reptile salesmen know about plants though.

The reason I asked about brown leaf tips is because that's often symptom of excess salt/s. Not necessarily definitive but it does suggest it's a possibility. Calcium in the water may actually be a good thing with coco fibre, which can be deficient and plants do need some, but I was pondering whether that could be contributing to the problem. Having said that, I have very hard (lots of calcium) water here and I'm not seeing salts on the surface of my houseplant soil, but then again they're in pots so have drainage whereas yours don't. In the field behind our house there are naturally occurring calcium salts on the soil surface of the poorly drained areas.

Since you're seeing brown leaf tips maybe I would replace the plantation soil with something else after all, since you can't flush it. Are there any garden stores nearby who could point you to something suitable that's available there?