Backyard Aquaponics
A place to discuss aquaponics

were all those systems comparable?

what you are saying goes against physics.

Re: Mr Damage - how does that comment rate as 'evidence' in a F&D conversation.

It is simply a function of media. Blue Metal or Pea Gravel - it all gets hot.
No-one would even attempt to argue that a blue metal F&D was cooler than an expanded clay CF.

That is simply another advantage of Expanded Clay not an argument for or against F&D.

I prefer F&D with clay for my systems, but if I was stuck with rock media then I would run CF in hot weather simply to keep the grow bed temps down. I have used cracked pea gravel in F&D and it heats up and seedlings/plants don't like it.

works other way in early spring (like now) when you want some warmth in among the roots.

Would the F&D beds have an evap cooling effect on the system when it's warm?

perhaps yes.

but my experience with (tubes not big bed) F&D was that high surface area = massive heat sink.

It's the evaporation that gives you the cooling. Tubes don't give you much of that and others have seen these raise the temp as well (TCLynx comes to mind). I don't think the grow beds will have a lot of evaporative cooling either but I could be wrong and I know how you run them matters - I don't remember how it worked out though . Someone around here has this figured out already. For what it's worth, Trickle towers/Bakki Showers are better for cooling and they're good at nitrification - Dasboot has one of these in his thread but it might be a challenge to find the posts showing the build.

Hmm...

Some reason I thought I'd read folks saying F&D ran cooler for them but I've never seen the reasons spelled out.

RE: Trickle Tower/Bakki Shower in Dasboot's system... I think this is the thread:
viewtopic.php?f=18&t=16235&p=541899&hilit=Trickle+tower#p541899

Page 83 and thereabouts... of Dasboots 'Crappy Basil growers are us' thread.

Spot on:
viewtopic.php?f=18&t=16235&hilit=Trickle+tower&start=1230#p517136

Update for that here but I'm not sure you'd want the extra layer he added (my guess is probably not) - http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=16235&hilit=Trickle+tower&start=1785

Actually looking at that part too... may need to consider it. We don't normally break 40C/110F+ but there are those occasional summers.

Well I went with a flood a drain system with two grow beds, fish tank and a sump tank. System works great and I have had my first crop of very big fat juicy strawberries. Just planted a cherry tomatoe plant today to see how I go with that.

I'm back! lol

Can't believe I was away so long but, life...

How big is the difference in oxygen saturation between F&D and Flooded beds?

Was hoping bell siphons and a trickle tower would limit the need for air pumps and stones.

Welcome back. I'd like to know about the oxygen levels as well