DIY grow sponges/media

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JayneR13
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Location: Wisconsin zone 5B

DIY grow sponges/media

#1

Post: # 66945Unread post JayneR13
Mon Apr 04, 2022 10:14 am

Hello everyone,

I'm new to hydroponics so I have a lot to learn! I don't really want to keep buying replacement sponges and based on preliminary research, they don't seem to be that hard to make. Would you all mind sharing how you make yours? What materials do you use, how do you process them, are they reusable? Thanks for any information you can give!

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GoDawgs
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Location: Zone 8a, Augusta GA

Re: DIY grow sponges/media

#2

Post: # 66962Unread post GoDawgs
Mon Apr 04, 2022 2:21 pm

Welcome to The Junction! I don't do hydroponics but I'm sure there are some folks here who can help.
Garden and learn. ;)

JayneR13
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Re: DIY grow sponges/media

#3

Post: # 67344Unread post JayneR13
Sat Apr 09, 2022 9:48 am

Garden and learn indeed! I'm doing some research on hydroponics in general and the Kratky method, and I see people using a large variety of materials. Rock wool seems pretty standard if a bit pricey for seed starting, or start from seedling and use coco coir or perlite to hold the plant upright. I've also read about sphagnum being useful and since I also grow carnivorous plants I do in fact have some I could play with. But again, any tips from more experienced growers would be greatly appreciated.

rossomendblot
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Re: DIY grow sponges/media

#4

Post: # 67366Unread post rossomendblot
Sat Apr 09, 2022 1:03 pm

I've got some basil seedlings growing Kratky style, my first foray in to hydroponics, in 2" net pots filled with clay pebbles to support the plants. I took the idea from this video and threaded some paper towel through the bottom of each net pot, leaving enough sticking out of the bottom to act as a wick, and made a paper germination 'bed' on top of the clay pebbles.

The clay pebbles are reusable which is a bonus. I did think of perlite but read somewhere that it would float without something weighing it down.


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pepperhead212
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Re: DIY grow sponges/media

#5

Post: # 67375Unread post pepperhead212
Sat Apr 09, 2022 3:29 pm

Welcome to the forum!

I grow deepwater hydroponics every off-season, to get herbs and greens, and have great success with them. I was not crazy about rockwool, or those brown cubes - I have much better success with clay pebbles, most of which I can recycle. For many of my plants - basil and other herbs - I root in a homemade cloner, but they can often just be rooted in a cup, changing the water every couple of days. But for things that start from seed, I use some coir - sphagnum would serve the same purpose - and I make a small layer on top of the clay pebbles, using some mesh fabric, to keep the coir in place, but it's open enough for the roots to pass through. Here are some photos from a while back, showing the coir in the baskets, 5 days apart when planting seeds:
ImageStarting seeds in hydro, 11-15 by pepperhead212, on Flickr

Imagegreens, started around 11-15 by pepperhead212, on Flickr

There are a bunch of other photos on that album - several of those same plants in the course of the winter. The way I make the coir layer on the pebbles is I leave about an inch empty space on top in the basket, then take about a 5 or 6 inch square if the mesh, and just press it in, and against the sides, then press some moist coir in, level with the top. Then I rinse it well - to get any dust out, then take some scissors, and trim the top off, leaving a little on top, as you can see.
Woodbury, NJ zone 7a/7b

JayneR13
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Re: DIY grow sponges/media

#6

Post: # 67423Unread post JayneR13
Sun Apr 10, 2022 10:54 am

Fascinating! Using a paper towel to wick up moisture for seed starting is something I'm going to have to try, and I've been considering using some form of mesh to contain the sphagnum. I've put two experimental sphagnum "sponges" into my IDOO unit, one with a seedling and one to try seed starting. The seedling is doing fine. We'll see how the seed germinates; the other benefit of the paper towel bed is being able to see if/when the seeds germinate. Both are in a grow slot that's a bit away from the pump. I'm also considering using my carnivorous plant soil mix, since a couple of the videos I've watched have noted the need for a slightly acidic pH. In fact, veggies in dirt like a pH in a similar range: 6.5-6.8 or so. I would definitely need a mesh of some kind to contain that mix. I might try some old pantyhose.

I did in fact set up some Kratky jars yesterday! One micro tomato and two extra peppers. I was determined to use what I had lying around the house, so I had to snip my 4" net pots to fit my 1/2 gallon Ball jar. It seems to be working so far! No transplant shock, but I might cover them just to keep the algae growth down. It's pretty cool to be able to look at the roots but I can move the cover for that. Yes the peppers look silly, so tiny in such a big jar, but they'll grow into it!
Kratky jar 1.jpg
Kratky jar 2.jpg
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