How to start a drip irrigation

Hugo Blocks are:

Amazon.com: Grodan "Hugo" Blocks (individual) - 6" x 6" x 6" w/ hole: Kitchen & Dining

Dutch Leach Trays are:

Dutch Leach Tray Kit, 6x40" (Hydroponics / Trays & Reservoirs / Trays)

Thanks for your input.

ah, 6" cubes. I know that the 'Mr Green' cannabis videos (which are otherwise pretty good and do have some good basics in them for new growers) on YouTube feature drip-feeding large blocks like this, but I don't think I'd do that unless the drip feed was constrained to just a couple of minutes a day. The problem is that RW is highly absorbent and will allow water to displace all the air in the material. This will result in an overwatering condition if the drip is permitted to do more than dampen the RW block.

Drip feeding is most useful when using clay pellets as they hold next to no water and thus can tolerate frequent if not constant drip feeding; a drip ring is a very useful bit of kit for drip watering. They also allow watering of the pellets around a 40mm RW block without watering the cube.



However, drip systems have one fatal flaw; drippers will clog with nutrient salts unless cleaned at least every other day. Single-point emitters are particularly problematic, but drip rings, which have numerous emitter holes, are a bit safer to use if you just gotta drip feed.

I used pots of RW floc for a number of years. Pre-soaking pots of floc with a 5.0 soln is impractical because it's difficult to effectively drain the pre-soak soln from the material. Same problem with big RW blocks. If you can't pre-soak, the pH will bump up about 0.1 per day. When using RW floc, I just put up with the pH jumping and corrected it when it rose to 6.0.

Thanks Al - so what's best then - hand-watering?

If you were going to use big RW blocks or slabs as your main media, I think it'd probably be good to use a flood system which only floods to about 50mm deep and for fairly short durations, 2-3mins tops.

Thanks - any idea how to set that up for two of those 40" dutch trays? A pump and a bucket for the res and how to control the flood depth within the trays?

Thanks again Al.

This is a basic diagram of how flood systems work:



Get fill/drain and overflow fittings at a hydro shop or at a hdwe store.

The fill/drain fitting (on right) has a barbed 13mm (1/2") fitting which suits a piece of common garden hose.



The overflow is a bulkhead fitting with a ~19mm (~3/4") barbed connector which suits a length of rubber tubing (not pictured in animated diagram). The length of the overflow tube sets the flood depth. The bit of tubing fitted to the bottom of the overflow ducts water back to the tank when the flood level is above the overflow tube length, preventing dribbling water noises.

Thanks Al - fantastic diagram. The dutch leach trays come with two elbows and two plugs for the two holes at the end of each tray. These are apparently capable of being modified to fit an ebb & flow but I don't see how - will your method work with tubing attached to one of the elbows?

I'm not so sure that will make a good flood tray. It looks like it has two channels that are not connected by any cross channels. If there's no cross channel connecting them, if you put the fill/drain fitting through the floor of one of the channels, the tray will drain but the other channel will remain full of water. The fill/drain fitting must go through the floor of the tray so water can drain out fully.

Al if he branches the two drain holes (at the side of the tray) into one flood pipe coming from his nute pump, then measure up, and drill a hole above them, for his overflow pipe, would that not work for him?
Just a thought.

Good idea fitzy. A 't' with a couple of elbows would connect the fill line to the two channels and allow them both to drain. It may not drain fully to the channel floor level with the fill/drain conns through the side, though.

Thanks for your help on this - the holes are at the end of the trays near the bottom. With the elbows inserted, apparently you turn them up to flood and down to drain. Using your suggestions, should I try to connect a pump to one of the elbows and turn the other one up? Sorry to keep going on this but I still am not quite sure how this works. Thanks again for your assistance .

irie41 said:

Thanks for your help on this - the holes are at the end of the trays near the bottom. With the elbows inserted, apparently you turn them up to flood and down to drain.

Click to expand...

And how exactly are you going to get a timer operating your pump to twist these things around for you? Answer: You won't.



It needs to be organised similarly to the animation, with a fill/drain and an overflow.

What fitzy was suggesting was doing the fill/drain via the two holes in the ends of the channels. This means there will be a 1/2" hose going from the pump to a tee fitting and a couple of short lengths of hose from the tee to a couple elbows which are fitted to the two holes in the end of the tray. There will have to be an overflow fitting installed through the floor of the tray to set the max flood depth.

Using your suggestions, should I try to connect a pump to one of the elbows and turn the other one up?

Click to expand...

No, that won't work. If you fill via one of the holes, it'll be draining through the other and water level will not rise to your overflow tube level.

Touché Al, Touché.

I think I'm going to hand water them. This is too much hassle for those smaller trays - better for an actual tray bed with the space and cross channels for drainage it seems.

So - with hydroton on the bottom of the dutch leach trays to improve root drainage, and at the risk of sounding even more like a novice, would the fill level for a manually watered bottom flood be the same?

Thanks again for being patient with an obvious noob.

If you put an overflow fitting on the tray and fill/drain through the two holes by using a tee fitting, it should work fine. Automating watering is a very desirable thing and not that hard to do. Loss of plants or damage from wilting them through forgetting to water sucks ass.

Don't put pellets in the tray. They won't improve drainage, but they will give a place for roots to knit into, outside of your pots, defeating the purpose of having pots. You only need pellets in the pots.

I might not have chosen this particular tray for use as a flood tray, but you should be able to make it work with a tee fitting providing a path to both channels in this tray, as has been described.

I am not using pots - just the 6" hugo blocks, which fit the trays exactly.

How many times a day do the trays need to be flooded and is it still 50mm?

Thanks again.

Hey Al... quick couple questions buddy!

I'm only using an 400w HPS light throughout my grow... and I'm kind of stunted at my first week... I'm using a cut out clear gallon placed over the top. I soaked them in a cup of water till it cracked and put it in a RW 1" cube and am giving it 18/6hrs of light with the light a couple ft away. I don't have a pic to share, but this is just bag seed before I start playing with the white russians I ordered till I know I can get the hang of it!

Also, I waited for the seed to crack when I soaked it (basically till it sank) than put it in the RW cube about 1/8" deep... I saw the tap root growing sideways after a day... I got impatiant after 3 days and did a little surgery and removed the seed casing myself... but now it's not to happy! Should I continue this method? I haven't had any luck germinating in the paper towel on my cable box yet!

irie41 said:

I am not using pots - just the 6" hugo blocks, which fit the trays exactly.

Click to expand...

I was kinda hoping your tray was large enough to suit some pots. If you could fill pots with pellets and put the RW blocks on top of them, when the roots had knit into the pellets, the system could flood the pellets beginning with 5x/lights-on. If you fill the tray with pellets, you can accomplish the same thing but the plants won't be movable until harvest.

If you use the RW blocks only as the growing medium, flood 1x at lights on, to about 50mm. RW blocks are highly absorbent and wick up water in no time at all. Doesn't take a very deep flood nor a very long one to saturate RW. When the plants are larger, you may want to flood at lights on & at lights-on +6h.

illusionz1 said:

Also, I waited for the seed to crack when I soaked it (basically till it sank) than put it in the RW cube about 1/8" deep... I saw the tap root growing sideways after a day... I got impatiant after 3 days and did a little surgery and removed the seed casing myself... but now it's not to happy! Should I continue this method? I haven't had any luck germinating in the paper towel on my cable box yet!

Click to expand...

There's any number of different ways to get a bean to crack, you know of at least two! Use whatever works for you.

Resist temptation to remove the seed hull. As you've found, it's not a good idea to rush things, you can damage the seed leaves and slow the thing way down.

Al B. Fuct said:

There's any number of different ways to get a bean to crack, you know of at least two! Use whatever works for you.

Resist temptation to remove the seed hull. As you've found, it's not a good idea to rush things, you can damage the seed leaves and slow the thing way down.

Click to expand...

Ya man! You,ve nailed it! Lastnight I ditched the one I've rushed and started the towel method for the WR's.

So far you,ve confirmed it... As a newbie, I think I've just learned the most important lesson... PATIANTS! I know I rushed the last seed cuz I was worried but really, it just needed more time... Lessons learned!

But I do not want to mess these WR up at all... Do you think they'd be ok to sprout under a 400w hps about 24" from the light or will it be too much? Cuz after all, I'm tryin to grow, not broil them : ) !!!

'Prciate your help my friend!

Cheers & Tokes!

illusionz1 said:

Do you think they'd be ok to sprout under a 400w hps about 24" from the light or will it be too much?

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Too much. Use fluoros for seedlings.