rockwool seedlings - plant in hydroton with/without rockwool?

[claude saunders]

I'm starting up an aquaponics system for the first time. I have a bunch of seeds started in rockwool plugs. When I go to put them in the hydroton growbed, should I gently strip away the rockwool, or just plant the whole rockwool plug? Any advice appreciated!

A side question - I was surprised how quickly the seeds sprouted in the rockwool. Much faster than any seedlings I've started in peat plugs. I used water at 5.5 pH to soak the plugs. Could the low pH water be responsible for the faster sprouting?

 

[april Dawson]

I just started seeds in rockwool dipped in fish tank water with a pH of 7.8ish so i don’t think it was the Ph. They all have legit leaves and i planted them  on the 24th in the morning, so just over 48 hours ago. Curious to see what the answer is.

[Eric Warwick]

Just stick them right in. In the future just broadcasting the seeds will work. I've used this method in my hydroponic system with a high germination rate. As for the pH, peat is acidic and you most likely neutralized the basic rockwool by sticking them in acid, so maybe. I don't think it makes much difference until you get to extreme high or low pH. 

[TCLynx]

ya what Eric Said

[Bob Vento]

By broadcasting do you mean sprinkling the seeds onto the Hydroton? What keeps the seed from washing away into the fish tank in a flood and drain system?

Eric Warwick said:

Just stick them right in. In the future just broadcasting the seeds will work. I've used this method in my hydroponic system with a high germination rate. As for the pH, peat is acidic and you most likely neutralized the basic rockwool by sticking them in acid, so maybe. I don't think it makes much difference until you get to extreme high or low pH. 

[claude saunders]

I actually did switch over to broadcasting (from rockwool), but not for everything. My lettuce seeds germinate really well (and quickly) by broadcasting, but some other things have not. I'm sure some of the seeds wash away, but hydroton has lots of little nooks and crannies and the seeds seem to stick. Either that or they "bob" until the tap root comes out.

[Eric Warwick]

Natural forces. This is the best explanation I can give without my head being up my, well you know where.
Bob Vento said:

By broadcasting do you mean sprinkling the seeds onto the Hydroton? What keeps the seed from washing away into the fish tank in a flood and drain system?

[Bill Moore]

So far, I have not had a single seed germinate in the rockwool cubes I bought.  Zero.  I have tried them in both the Flood & Drain bed, the NFT cups and on a raft in the sump tank.  I have far better luck just sowing in the hydroton.  Any ideas what the problem is?

[claude saunders]

Hmm. Works pretty well for me. The directions suggest soaking the cubes in 5.5 pH water, which seems to make a big difference. I tried to start a set of seeds in rockwool once and forgot that part, soaking them in our 8.0 pH tapwater, and they didn't germinate well. Also make sure the cubes stay moist (to state the obvious). And put them under a light to warm from above, or I think warming from below will work as well. Just some thoughts.

[claude saunders]

Ah, after re-reading your post, it seems you are putting the rockwool in your beds right away. I put the rockwool in a clear-plastic covered seedling tray (with drain holes), and let that sit under a light for about a week. Only once I have a good sprout with a couple solid leaves do I plant them in my grow bed. That may make a difference, since the cube can remain at 5.5 pH, whereas if you put in your grow bed, it's probably at least a point higher and maybe less warm.

[Bill Moore]

Good suggestion.  I'll try that.  Thanks.  And you're right, I was putting them immediately in the medium which is running a pH 7.3 or so.

bill

[TCLynx]

If you are able to seed directly into the grow bed, why bother with the rock wool?  Save the money and just direct seed.  The use of seed starting media is generally more appropriate for when you can't immediately plant into the beds or when you are planting into a method that doesn't take well to direct seeding or if you need to provide extra warmth for better germination for certain crops and things like that.

[Vlad Jovanovic]

Man, this is kinda ironic... but when I start seedlings (for any non-AP-media bed system...dirt garden, hydro, organic-hydro) I generally start them in a net pot or whatever container with just hydroton. This has worked as well as any other media I've ever used.

Lettuce sprouts ridiculously quickly in any medium, but for things like peppers, and toms where germination takes a good deal longer (I'm not real patient) I'll pre-soak the seeds in a solution of water with a little bit of Hydrogen peroxide for a couple hours up to overnight. This seems to speed up the germination process a bit and has the added benefit of allowing you to weed out potentially cruddy seeds. I'll only use the seeds that sink to the bottom, and not the ones that float. One or two cap fulls of 3% peroxide to about a cup of water seems to do the trick. (Helps break down the coating a bit I think). Tannic acid can probably be used also. (This is the acid that is found in pine needles, oak leaves, driftwood, a cup of tea etc)... 

The thinking here is that part of the reason why seeds that a bird shits out do so well, (in part) is that the acidic environment of the birdy's stomach helps eat away some of the seed coat, so that the seed can emerge easier/quicker.

This may or may not have something to do with your OP. IDK.