The tank experiment...

I am going to try a tank experiment. I am hunting for a cheap 3 foot glass tank that I will fill with the cacti (homemade) mix and plant various purchased cacti of similar species (probably gymnos). I will use a fluro glow light for 14 hours per day. But because I live in the tropics I will provide no extra heat. Though I will have a heat cord that I will wind through the sand for emergencies (it once dropped to 12'C in Cairns, truly!!!).

I figure over summer I turn the air con on over night for sleeping, so that will mimic the wild where the night goes very cool in the desert.

I will provide water via a mister and the built up humidity in the tank.

Two questions:

Would you leave your cacti in pots - that way you can bury them and remove them as required and they can be positioned outside if need be - or do you think free rooted will be fine?

Secondly - do you have any experience in this, is it a worthy experiment, what sort of things would you do?

I will look at setting it up if I can get the tank within a week or so. So I will just use pre-grown cacti (like the $3 ones from Big W or Bunnings).

Cheers

Slim

Drainage?

Drainage shouldn't be an issue - mainly due to the fact I will have rocks and pebbles at the bottom, water will only be provided by mistings and the humidity.

Though you do bring up a valid point. I guess so long they're above any pooling water (if it was to occur) the water would evaporate and cause capillary action or at the very least evapotranspiration and evaporation.

I can't see that working if you don't water properly, if you can provide adequate drainage that's another story. Cacti actually do need water in the growing season. Even Arios definitely benefit from it, the roots wither and die otherwise.

It'sw a fine line between water and death, a fine fine line lol

What do you want to achieve from this experiment ? It's not an experiment unless you have an end. I'm guessing accelerated growth ?

On watering...ALL cacti need water, misting humidity etc will not work and will actually encourage rot.

Not just accelerated growth but growth full stop, flowering, etc.... Just general well being of the plants. The experiment is mainly to see if it works...

They will be watered sufficiently but I am thinking that if the soil was above rocks drainage would be adequate - but some ponding could be expected I guess. I haven't worked that part out yet.

I guess I'd have to just be very careful with watering.

be interesting to see how this works for ya. By the way what are you doing posting on forums while your ment to be at school lol

The good news about having a student teacher teaching your classes is you can sit at the back of the class and post to forums

I have a 2 foot tank, I am going to organise a light etc... From there I will either a) grow from seed or b) buy a few cacti.

I was very lucky - I wrote to Yates because I couldn't find the cactus seed mix that they sell. They said they didn't know anyone in Cairns selling it so they sent me out a pack free of charge!!!

I figure I could scatter this seed inside the two foot tank and see how things went.

Can I now have your thoughts on that?

My personal opinion suggests I should use a selection of pre-grown cacti. But maybe from seed will be better???

I'd be concerned about the microclimate in a small tank. Whilst some species like pereskiopsis will probably thrive, I suspect that other species may succumb to rot under those conditions.

However, you could use that setup for the best of both worlds - a grow tank for cacti grafted to pereskiopsis. You'll get accelerated growth to flowering in a short time... in theory.

Growing from seed is your best option as seedlings are well adaped and will actually thrive in the "tank" envioronment your creating. Just be careful you don't over do the light and you will need to be very careful about drainage. I think mould will be a poblem, it is common for green growth like patches to appear near and around your cacti seedings and so long as it grows slower than the seedlings you have no problem. Just keep it in mind.

The Experiment has Started - Initial temperatures and set up seem ok.

Well here it is - sorry Hellonasty, I got your message too late, I had already set up the enclosure with 6 cacti (gymnos and echinopsis).

Now, I'm not some cultivation expert or anything, and recall this is an experiment (which I am sure has been tried on many occassions and maybe even worked).



Now sorry about the shot - I only have a macro lens at the mo so I couldn't get a better shot

There appears to be condensation in the front centre, this is not the case, it's in fact some old silicon (I had used this tank with a seperator so I siliconed in a seperator).

The temperatures - the ambient temberature drops to around 20'C over night and heats to around 32.5'C during the day (maybe higher on a hot day). It is out of direct sunlight and is only lit by a 10,000K light bulb. This is the sort of light bulb that enhances coral - but I am unsure of whether it is suitable for growth.

Some additional underground heating is supplied for those very cool mornings we sometimes get in the tropics. The heating is a 5m heat cord (about $14 from a pet shop) and that is buried under the soil. Now down't let any physics teacher tell you that water and electrcity are no good. This heat cord is well protected.

Plus the magnetic field it produces may also encourage growth (I am sure I read that somewhere - could be wrong).

The overall heat mostly comes from the light above (so similar to the sun).

Watering - I haven't really considered it yet. The potting mix was naturally a bit damp anyway. I think I will water lightly every couple of weeks (??).

The drainage issue - outside of the frame of that shot shows the soil sitting on top of a bed of rocks. It is apparent if you're over watering - but with enough heat that water will soon return to the bottom of the mixture and enter the plants that way. The increased heat (using the heat cord) should prevent rot (hopefully).

The results... I don't yet know what I will base results on, but initially whether or not the cacti actually grow - there's a few pups in there just to see if they take or not. And there's control cacti outside. So I do have a measure.

I also want to see if they'll flower.

I have found that the high humidity in the tropics and the huge amount of rain here may make it difficult to grow cacti in outside conditions. So this container way of planting may be the only way to enjoy permanent fixtures of cacti for me - we'll wait and see.

So there's a few things to evaluate. I will keep you posted by means of this thread as it happens.

At the moment it's a toastey 29.5'C sitting under the light - I would think that's good conditions for growth.

All your comments, criticisms (constructive) and advice are welcomed in this thread.

see what keeping herps do to us, we dont keep plants in terrariums, we keep them in enclosures lol. looks good mate

lol you need a couple collared lizards in there!


i use tanks for grafting, cause the humidity stays high. my guess is teh entire setup can work absolutely fine EXCEPT not enough light! and if you start putting lots of light in there i would bet it will get VERY hot (which is ok) and VERY humid (not that great).

just a guess.

it's open at the top Kada, so I guess I can double the light??? Fluros dont put out too much heat, but they clearly do make a difference. I might invest in a double fluro header and still leave enough room for moisture to escape.

more lights are good, but even flouros produce decent heat when on all day. thats fine, but humidity may be an issue...here, even if there is no extra water added, i find condensation on teh walls just from the heat inside the tank and the rooms humidity. not sure about your area....but if your tropical just keep an eye out for it

are you planning on any lizards in there? you got some kick ass herps out there in Aus!!!!! ya bastids!

I have several snakes (as pets) and about 2 million asian house geckos (wild). I always get an array of green tree frogs and hundreds of other assorted frogs. But alas, i also get too many toads

Maybe I can put a toad in there haha... It's certainly not illegal to keep them as pets, it's just illegal to ship them out of state.

I was thinking of scorpions actually. My girlfriend did elude to the fact it would look cool with a scorp in there.

But I was not to sure if it would be able to escape easily. As it doesn't have far to climb that's for sure and I don't think I can provide the right temperature/humidity.

So far the temperatures range from 20'C (first thing in the morning) to 34'C around 7pm at night (when lights go out).

The large gap (no lid) between the soil and the light lets all the humidity out. The soil heating also prevents water from condensing on the cooler glass. Plus the desert like conditions.

They were given a splash of water (enough to wet thr top few cm of soil around the cacti only) last night, and that's nearly all evaporated now. Condensation after nearly a week is still nil. So - the experiment continues.