closed-system rewatering and plant wastes?

[dethswatch]

I've got a wardian case setup that mists and waters and then drains into the same container. The water is exhausted every week so it gets new (tap) water at that point.

I think Ray mentioned that this wasn't great due to plant wastes, etc.

What sort of wastes are we talking about and how would I go about analyzing the water to determine to what extent I've got which wastes?

Can anyone tell me about plant wastes or point me in the right direction so I can read some more?


Thanks

[rbarata]

If one plant get infected by a pest, reused water will spread it to all plants.

[fishmom]

If you are fertilizing, or even from tap water, salts can build up over time. Do you see white deposits on the planting medium? If you have a TDS meter, you could check to see if the numbers change from the beginning of the week to the end.

[Ray]

Plants wastes and mineral residues are the least of the problem. As was mentioned, pathogens are the real danger.

Closed-loop systems are fine for plants with short maturation cycles that get harvested, but a long-term plant like an orchid is a whole different critter.

[dethswatch]

Originally Posted by rbarata

If one plant get infected by a pest, reused water will spread it to all plants.

yes, luckily, that hasn’t been an issue.

---------- Post added at 09:20 AM ---------- Previous post was at 09:19 AM ----------

Originally Posted by fishmom

If you are fertilizing, or even from tap water, salts can build up over time. Do you see white deposits on the planting medium? If you have a TDS meter, you could check to see if the numbers change from the beginning of the week to the end.

Yes, the tds are all within reasonable ranges before and after. But that’s a good point.

I only have wood and media and do not notice any buildups.

Thanks

---------- Post added at 09:21 AM ---------- Previous post was at 09:20 AM ----------

Originally Posted by Ray

Plants wastes and mineral residues are the least of the problem. As was mentioned, pathogens are the real danger….

Thanks!

[Swimmingorchids]

Originally Posted by dethswatch

yes, luckily, that hasn’t been an issue.

Hasn't been for me either.

Ray has a point and once one plant is affected all plants get affected but for the simplicity of reusing water I have adopted the approach to my orchids as standard too.

I would not recommend the procedure but so far about 6 months in no issues whatsoever. Saves having to measure out the nutrients and adjusting the water every watering

Of course I know if I get a problem with 1 - it will, not necessarily - but most likely eventually spread to all others too.

[plantzzzzz]

Originally Posted by Ray

Plants wastes and mineral residues are the least of the problem. As was mentioned, pathogens are the real danger.

Closed-loop systems are fine for plants with short maturation cycles that get harvested, but a long-term plant like an orchid is a whole different critter.

Are there ways to disinfect water in a closed-loop system?

Could you bubble ozone through it, or would that harm the plants?

[dethswatch]

Originally Posted by plantzzzzz

Could you bubble ozone through it, or would that harm the plants?

Aren’t the aquarium guys using UV lights to kill pathogens?

[Swimmingorchids]

If I have encountered a problem in the past I would use hydrogen peroxide at a very low dose but I am thinking of going lower still with orchids.

I am going to try 40ml of 3% HP per liter of water in future...

I think that works out to roughly 0.1% hydrogen peroxide. Wouldn't use it permanently.

[camille1585]

Originally Posted by dethswatch

Aren’t the aquarium guys using UV lights to kill pathogens?

Many, many horticultural businesses use UV to kill pathogens in water. All those growers who use ebb and flow to water their plants will drain it back into tanks to recycle, otherwise it costs way too much in terms of both water and fertilizers. They will usually use more than 1 type of method, and UV is often one of them.