Too much condensation in flasks

[NatalieS]

I did a quick search but couldn't see anything related to this question. I was wondering if anyone had any tips or tricks for reducing the amount of condensation in flasks?

I've been experimenting myself with flasking this year and have some nice bulbo protocorms coming along. I was very pleased with this first experiment so I've bought one of the Kew books on growing orchids from seed and have flasked some more seeds. The one thing I always seem to have a problem with is lots of moisture in the flasks which then creates lots of condensation when sitting on the heat mats. The Kew book recommends keeping the temps even to reduce condensation but when the room the flasks are in is much cooler, it's hard to stop it from happening.

Just to mention a few things:

1. My media is not runny - it sets very nicely
2. Before I sewed the seeds I tipped off excess water and wiped down the lids

I realise there will be some condensation, but why too much is a problem (for me anyway) is because:

1. It makes it very hard to see what's going on in the clear polypropylene containers
2. Excess condensation can eventually lead to contamination

Any suggestions would be most welcome. Thanks in advance.

[31drew31]

Condensation as you know is a byproduct of temperature differences. Maybe you could place the flasks in a temperature controlled plastic bin or aquarium. Condensation would then gather on the bin instead of your flasks.

[lepetitmartien]

As I understand your issue, the condensation is inside the flasks.

The only way to get rid of the issue or control it is either to prepare the flasks in a little cooler environment or to keep the flasks seeded in a hotter environment.

Unfortunately for you, your preparation set up is making a wet atmosphere that crosses the dew point once left for germinating.

I'm not a genius of CIV, but there must be tricks to care of this but I prefer someone with experience giving them.

[isurus79]

I think you are just going to have to keep the flasks in a warmer environment for now. Next time you will have to flask your seeds in a lower humidity environment.

[Bloomin_Aussie]

The above suggestions will certainly help but it sounds as though you are getting too much moisture in your containers from the beginning considering you are having to tip excess water out. How are you sterilising the prepared containers?

[NatalieS]

Thanks for the replies everyone. From your suggestions I'm starting to gather that the relative humidity where I live might be playing a role (at least 60% even in a centrally heated apartment).

Bloomin_Aussie, I sterilise my media using the microwave method as per the three part Youtube series. Just like in the video, the containers go straight from the microwave into a bag which I've sprayed bleach into. I leave them with their lids slightly open and sealed in the bag until they are cool. A lot of the condensation forms in the bag instead of the containers but I still get loads of moisture in the containers. Once they're cool I move them to my makeshift 'glove box' and again try to remove as much of the moisture as possible before sowing.

I guess it's just the amount of moisture in the air. I might try moving them to a sterile box and leave the lids off for a while with the heat mat on under the box. I don't have anywhere that I can keep them in a controlled environment on a permanent basis.

[Ray]

Are the flasks vented? Whenever I've gotten jars or Ehrlenmeyer flasks, the lids or corks have a hole in them. The holes are either stuffed with cotton or polyester batting then the top covered in aluminum foil. In the case of a thin metal or plastic lid, the holes are covered with an adhesive bandage.

On the assumption that yours are not vented, what makes you think the extra moisture could be a source of contamination? If you sterilized it, and it's trapped in the flask, where could the pathogens come from?

As a general comment: constant, reasonably warm temperature and moderate lighting is important for germination and growth. Letting the flasks cool at night is not helping the process at all.

[NatalieS]

Originally Posted by Ray

Are the flasks vented? Whenever I've gotten jars or Ehrlenmeyer flasks, the lids or corks have a hole in them. The holes are either stuffed with cotton or polyester batting then the top covered in aluminum foil. In the case of a thin metal or plastic lid, the holes are covered with an adhesive bandage.

On the assumption that yours are not vented, what makes you think the extra moisture could be a source of contamination? If you sterilized it, and it's trapped in the flask, where could the pathogens come from?

As a general comment: constant, reasonably warm temperature and moderate lighting is important for germination and growth. Letting the flasks cool at night is not helping the process at all.

Hi Ray. No, the flasks are not vented yet. I know there is a lot of debate about whether or not gaseous exchange is necessary for flasking, but most agree that it isn't necessary for germination at least.

As to where a pathogen can come from, unless the lid is absolutely 100% sealed, there is the chance of contaminants/pathogens sitting on the outside of the container coming into contact with condensation accumulating in the tiny gaps that might exist between the lid and the lip of the container. From there the excess condensation could drip onto the media and the pathogen could then grow and spread (I've seen this happen with one of my earliest flasks). This is less likely to happen if there isn't a lot of condensation in the flask. I think most commercial flaskers will put some kind of sterile shrink wrap around the edges of the lid to minimise this from happening (if using plastic containers anyway). Of course the container could be well sealed, but even just handling the plastic container could pose a problem (eg. you deform the sides of the container very slightly when you pick it up, but the lid doesn't necessarily deform with the sides, etc.)

As a hobbyist flasker with basic equipment, I don't think I could guarantee that my flasks are 100% sealed. I'd therefore want to do everything I can to minimise contamination. I can definitely find better materials to work with, but it would involve a small investment and I'm just experimenting at the moment.

I take your point about keeping the temperature constant. I would disagree that a couple of degrees temperature drop at night would prevent germination though. I have some protocorms growing on very nicely which were germinated under normal temperature fluctuations. Everything I've read so far about germinating orchid seed just gives an average temperature range for germination. In fact, the only reason that I've read so far for keeping the temp absolutely constant is to prevent condensation. I'm only going on what I've read and my own experiences to date and am always eager and willing learn. I will challenge why something is done a particular way though - advice is good but reasons are even better.

[zxyqu]

Well I'd recommend going ahead and investing in shrink wrap. It's great stuff, and provides an extra layer of protection from potential contamination. As to Ray's comment of temperature stability, I assure you if there is minimal temp fluctuations (for phals at least), you'll get much more and consistent growth from the seedlings especially. If they dont ever really "slow down," you'll be deflasking and blooming in 2-3 years. I'm sure a few degrees aren't going to ruin anything, but a summer to winter night temp drop will surely slow everything down.

[NatalieS]

Originally Posted by zxyqu

Well I'd recommend going ahead and investing in shrink wrap. It's great stuff, and provides an extra layer of protection from potential contamination. As to Ray's comment of temperature stability, I assure you if there is minimal temp fluctuations (for phals at least), you'll get much more and consistent growth from the seedlings especially. If they dont ever really "slow down," you'll be deflasking and blooming in 2-3 years. I'm sure a few degrees aren't going to ruin anything, but a summer to winter night temp drop will surely slow everything down.

Thanks for the additional info Jarad. For my peace of mind I will be looking for some suitable shrink wrap or heavy duty cling film. It's a pain in the bum trying to find basic supplies in this country through.

Do you think the phals do better with constant warm temps because they tend to be warm, slow, growers? I'm not germinating phal seed but I'm curious.

Being in a heated apartment, the ambient temp never really drops below 20 C - occasionally high teens on a cold night. There isn't too much of a fluctuation, but perhaps I should invest in a thermostat for my heat mat anyway. Unfortunately cost is always a consideration and when you keep investing in small pieces of equipment it starts to add up. I'm guessing you sell on your flasks or seedlings?