Hey, Horse, disregard what I said about access holes. Didn't know you were talking about a recirc DWC system. You can check / balance at the rez, of course... I reach in there with a small kitchen strainer and scoop out root particles and any other debris-- screw that $$$ cannazyme type stuff. Mechanical controls, baby!

Here's the airstones I found, plus an airpump Weez recommended which is very quiet, also Walmart, $13+ change.

[attachment=o230965]

I think those EC stones you have are the kind I broke. They floated real well, too, the SOB's... Dese mo' betta. :thumbsup:

I compared those 3 new stones and they were all similar, +/ - maybe 5%. One had a "lean" area in the middle (slightly more bubbles from the ends) but probably nothing I'd have noticed if I weren't looking real close. Total airflow seemed similar between the 3 stones.

But check it out: I tried to "tee" 2 airstones off the same air line, and 90% of the bubbles come out of the stone that's only 5% better in a one-to-one comparison. Obviously, the air's gonna take the path of least resistance, but I would have guessed they'd "share" better. Pneumatics noob, here...

Tha's why I showed ya the pic of the air pump. I put one stone on each pump, and I'm now evenly bubbled.

Punching your own holes in an airline for your pre-veg bubbler might be your best bet for even bubble distribution from a single air source. I would do it under operating conditions, though -- under water -- and start punching from the end furthest the pump. Evenly spaced holes are not gonna give you even bubbles in this instance. (Though, as W. pointed out, that doesn't seem real critical. I've got a 5" airstone, off-center, in a 5 gal bucket and it's doing a fine job, with even root growth despite the uneven bubble distribution and mid-80's temps.)

And how deep is that water gonna be? I think the bubbles will oxygenate the water better if they have to travel through it for a ways...

:thumbsup: HTH, Hermie
DreadedHermie Reviewed by DreadedHermie on . Show me your stones I bought these 6ā? stones by EC plus I put them in a pre-veg bubbler The problem I have is that they arenā??t consistent in delivering air either across their width or over time. I go in to check on things and one may have stopped bubbling altogether, I rebalance the air delivery at the manifold and the next time I return a different one may have slowed or stopped all together. They seem to get waterlogged. Rating: 5