Backyard Aquaponics
A place to discuss aquaponics

Ellie... normal hydro uses a 50mm net pot for lettuce known as an "LP50"

I've got another version of the same pot for floating raft.... esentially like the LP50 pictured below... but with the bottom 20-30% cut off...

I'll try and take a pic of it tomorrow if I get time... but you should be able to imagine it...

Seedling starter media.... in hydro... usually vermiculite.... some use a cotton ball with the seed sown in it... some use a coconut fibre product...

Choice may be dictated by your temperature... the latter two obviously retain moisture more than the vermiculite.....

You migh need to overhead hand water the media if you're getting hot during the day... until they germinate....

Most hydro operations actually germinate in a shaded area/lean-to and then transfer to the nft...

Hope this helps....

Thanks! Question: Once I have my cotton-ball seedling, do I just set the whole thing into the net pot? What keeps it from falling out of the bottom?

(By now you are probably beginning to think I'm a bit thick.. I assure you this is the case. )

Once I have this sorted out, I'm going to take pictures for the next person.. step-by-step.

-ellie

Some just nest the cotton ball into the top of the media, particularly vermiculite, hydroton... some fill the whole net pot with cotton wadding....

Moisture retention, temperature balance... yin, yang...

Pot filled with wadding will have an obvious "cappilary" affect considering a constantly running flow in the nft tray/pipe.... maybe not so good if your temperature is low... the seed can rot before or shortly after germination.

Maybe ok if you're not running continuously or if your temps are high... stops it from drying out... keeps the seed moist

Cotton ball pressed into vermiculite is maybe the best of both worlds as the surrounding vermiculite retains some moisture which in turn keeps the cotton ball/seed moist.

Sorry forgot your main question..... the LP50 has a bottom... the cutdown version for floating raft doesn't, so you have to adjust your media accordingly... cotton ball shouldn't be a problem (see notes above though).... or use rockwool or loose rockwool "floc"...

Don't know why i didn't mention that before

I often start lettuce seeds on cotton balls. Sometimes even in the foam egg cartons.

If you want to see some cheap hydroponic methods I've tried in the past, check out this web page of mine
http://www.hydroponics.tclynx.com/
I used yogurt containers as my "net pots" My media was really large grade perlite (don't use the small stuff as it will clog everything no matter what.) By making a wick from rayon mop string I was able to germinate the seeds directly in the net pots in the system.

As to your over population problems and need for isolation and issues with systems not being quite cycled yet etc. I feel your pain as I'm going through some of it myself. I've been testing 4 separate systems lately. One aquarium, My quarantine system, The barrel system, and the Big system.

An update:

The fish are happy in the aquarium, though the gripe about the reduced rations. I'm doing 20% water changes every other day. The ammonia is low, but nitrites are really high. The water has a lovely brown tint.

I'm having trouble with fish poop clogging my filter. This should be less of a problem when I reduce the stocking density.

I _assume_ the outside fish is okay. The water has greened significantly, and I cannot see the lower 1/3 of the tank. He has not floated up, it does not smell, and the food is still disappearing. Ergo he must still be alive.

I purchased some rockwool (part Number HMU02) cubes and a platic tray with a lid to start some seeds. I planted 12 lettuce and 9 basil. All have sprouted and are under a grow-light in the garage. I'm dumping the tray every day and adding 2-3 cups of aquarium water. Whether or not that will be sufficient for the plants remains to be seen.

Starting seeds: (hopefully this will help someone down the road.)

I broke off about 1/3 of the sheet of rockwool plugs, and rinsed it under tapwater. I then dumped the water out of the tray and added 2.5 cups of aquarium water. 1 lettuce seed went into each hole on one side of the block, and one basil seed per hold on the other side. The lid went on the tray, and the lot went underneath the bed (so the kids wouldn't see.) 48 hours later the lettuce had sprouted. The next day I bought an $9 4 foot fluorescent light (no reflector) from Lowes, with two $8 "Plant/Aquarium" bulbs. I hung the lamp in the garage and placed the plants on a child resistant shelf. That was 2 days ago. This morning I checked, and the basil was just starting to peek out of the holes in the rockwool.

Lessons learned:
-This is not that hard, and I was overthinking it.
-The tip of a pencil is handy for picking up small seeds and sticking them in rockwool.
-Seeing the little plants pop out of a seed and start growing is "pretty cool".

I'm going to keep these under the lights for maybe another week or so, then break up the rockwool slab into cubes and transfer them into the floating raft outside. I will probably only move 1/2 or 1/3 at first, in case the sun/heat kills them. There are not currently any provisions for shading the raft or growbed. Will this be an issue?.

Thank you TCLynx for the link. You have quite an ingenious approach, and I will probably steal some of your ideas in the future.

-ellie

One more note: These rockwool plugs are tapered, and should be self supporting in the holes in the foam raft.

Or you could cut down on their feed

Don't know what pump you're using Ellie.... but most people actually remove the "filter" pads from the pump... if that's what you're referring to.... we want to suck up the solids into the growbeds.....

Provides trace elements for the plants.... and gets it out of the fish tank so that it doesn't mess with the water parameters...

They will wilt, no matter how much water they are in, unless they are shaded.

Thanks for the feedback all. Tennessee is turning into Aquaponics country.

I have to clean the filter nightly, so I will try scrub-rinsing it into the DWC half-barrel.

Any suggestions for shading a half-barrel of lettuce and basil? I don't have a greenhouse.

-ellie

You can buy big round umbrellas made out of shadecloth - we use them to cover the drillers control panel

Update. I split off the line from the pump and plumbed in the dwc bed over the weekend. The reduced flow "broke" the autosiphon, so I had to go back to 1/2" line. That fixed it and the system is chugging away. It fills and drains about 8 times an hour.

The seedlings are doing well, but I think I didn't get the lettuce under the lights soon enough. They all have stems one inch or longer, and as the leaves grow they are starting to fall over under the weight. The basil sprouted later and doesn't have this problem, they are nice short plants.

So the question is: Is "leggy" lettuce worth saving?

One or two of the Basil plants has developed a yellow spotty appearance. I "think" I needed to cycle the water more frequently and it may have "run out" of nitrogen. That is the theory anyway. We'll see how they do outside.

I'm buying the foam board and another bag of gravel tonight. The plants, and another fish, go outside tomorrow.

I'll be digging through the "plants" section next, trying to sort out what I can seed in the gravel.

-ellie

I added the gravel and adjusted the siphon for the new level last night... Then the sky wrenched open and a great deluge fell. I will reattempt the raft construction and transplant tonight.

I have Piccies! Here is a fuzzy picture of the system in the rain. You'll have to imagine the other NFT growbed on the right, it is in the garage awaiting a scrub down.


And here are my seedlings. The leggy lettuce on the left is what I'm considering culling.


We (meaning the kids) bought corn, pumpkin, cucumber, tomato, and daisy seeds to add to the lettuce and basil collection.

Here is the system picture... or at least 2/3 of it .

leggy stuff seems to go OK, if you catch it early enough and give more light. My brocoli that went leggy is going good, it just sorta lies on its side