Bulkhead/In-line Replenishment Snag...

[scolley]

Originally Posted by zzapd

If the switch is resetting after a ten inch drop that is pretty good for a switch of that type. The 10 inch drop is only a change of .4 psi. A quality
industrial switch that costs about 300 will only get you down to a five inch
dead band.

Thanks! I was worried that I had bought something cheap. I guess I really didn't know what I was doing (again!), and am finding out along the way!

"Dead band" huh? That's what that range of pressure is between the two different spots where it switches state?

And it could be a 12" drop. I only did a quick measure once I figured out it was about 1/2 the height of my 75g.

[BlueRam]

Going for my merit badge for beating an idea to death:

This is the float valve I kinda had in mind:
http://www.automatedaquariums.com/lv_plc.htm

The idea being that a well placed hole drilled in the cypress and routed either at the very back (or through a bulk head) would provide ~1/2 accuracy.

[scolley]

Thanks BlueRam. I've seen those, and think they are a reasonable value solution. (I bought the better of my two peristaltic from those guys)

Problem is the "through the bulkhead" thing. Nothing else is going through a bulkhead without tearing down the tank. So I figure that's out now. And I'm kind of adverse to putting equipment in the tank anyway. That's why I find that new thread of Tom Barr's (about the CO2 microbubbles), it's all leading back to more crap in the tank. I don't like hiding stuff. I'd rather have as little as possible to hide.

Also, the range is kinda high. It's got that "dead band" that zzapd mentioned of 1.5 inches. Just like mine, it has to drop 1.5 inches before it know there's been a change (mine drops 10-12 though!). With 1/2 inch variance, that could be a range of 2.5 inches. Not terrible. But I'd like to get it tighter if possible.

But thanks for beating that horse!


I've got to try the "air pump" on a "T" that I mentioned a few posts ago. It just might work...

[BlueRam]

I could post this elsewhere, but I think the reactor is not a problem. From what I gather, the mechanism of getting CO2 dissolved changes throughout the photo period. For example, early, CO2 goes in just fine, however, at saturation, bubbles form in the reactor. Theses can either stay there (they make some noise), be blown out large bubbles (mine runs ~5* tilt. I can purge gas mid day), or the bubbles can be chopped up and run through again. I am happy with my reactor and am in the process of confirming Tom's observations. Not quite a full fledged idea yet, look for more in the proper post.

Your tank looks great!

[scolley]

Thanks pal. But the tank does NOT look great. It's got algae bad. What it does apparently is photograph well. I'm working real hard to remain calm on the algae issue. The BGA is back, and making me insane! My CO2 is in the forties, and most of the plants pearl everyday, so growth is good. It's just good for the algae too...

And to further the "I should post this somewhere else" theme...

I'm in full agreement about the CO2. I'm in the process of assembling an in-line device to inject those microbubbles in to my return line before getting blown into the tank. Parts on order now.

But if this idea that dissolving stops after some level of saturation is hit (30 ppm?) is not correct, then I just wasted some more money. So I look forward to your confirmation.

Now that the money is spent, it'd be nice to not waste time too.

[SCMurphy]

Steve you made it tough on us when you built this piece of art without a sump.

[scolley]

Yeah Sean, all in-line is a major PITA. That was my compromise, everything being a PITA in order to get stuff out of the tank.

Next tank will have a durso w/sump underneath - the compromise will be always having to hide the overflow. But everything else will get MUCH easier!

[lumpyfunk]

Could you put the float swich in your co2 reactor, when the pressure drops your co2 will (at least mine does) push out more gas due to the reduced pressure from the water level and trigger the float switch.

[scolley]

Lump - I gotta give it to you... THAT'S thinking out of the box! My reactor is not clear, it's white. But even still, when the CO2 is off, there should be no bubble there. And when it's on, the size of the bubble should vary with the speed the needle valve has been set to blow bubbles. And it the rate of change will vary as the water flow through the reactor varies with equipment added/removed in-line, and with the filter gunking up.

But it's an interesting idea.

I've pondered doing something similar for a while... taking an in-line container with a pressurized air pocket in the top and putting a float valve in it. But that has a whole lot of problems. Getting it pressurized, maintaining constant pressure, the size of the pocket remaining the same (not being subject to out-gassing or absorption).

It is a path that could be pursued. Thanks for the suggestion - it was certainly innovative. But I'm just not that courageous.

[jgc]

Not that I would want to build this beast – but…

You could use a pressurized chamber under your tank to remotely connect the float valve.

Oh latter thought - you would ultimately be trying to build a supper sensitive pressure sensor - no bets on if it would work.


Ok, figured out a way to possibly make a more sensitive switch, do not have time to draw it out though. Same basic concept as before, but with 2 differences. Increase volume of presure chamber - but decrease the diameter of the tube where the float switch is.

[scolley]

I think that's BRILLIANT jgc! But I don't think it would work...

Atmospheric pressure variations outside the tank would cause the measured level inside the chamber to swing - possibly significantly. It would take someone better informed than I to figure out how much.

If that variance proved to be small, I'd build it. Then the only thing that would have to be overcome is some sort of adjustment mechanism. Something to ensure that the float was sitting at the right level...

Maybe a very sensitive gas escape valve at the top, and a drain valve at the bottom, and a clear chamber, would be enough to allow you to visually align the water level with the float valve.

Great idea! I wish I know how much atmospheric pressure would affect that.

[jgc]

Yes, I know I hacked the design off a barmeter.

Actually though, think Boyles law will give me even greater grief. Suspect the water presure will vary a lot more than atmosheric. But heat the air in the presurized chamber - hehe you have a thermometer as well.

[scolley]

Originally Posted by jgc

Yes, I know I hacked the design off a barmeter.

If you knew it wouldn't work, then why, pray tell, did you suggest it? You made a nice diagram and everything. That's a lot of trouble to go to for a bogus suggestion.

I've got better things to do than figure out why something won't work... I'm looking for something that will.

[lumpyfunk]

I have no idea how this would effect the efficency of your wc, but have you considered an surface scimmer type tube (located behind your cypress stump of course) and just had a steady regulated inflow of fresh water from the unused bulkhead?

[scolley]

Yes - thanks - I have. There's all kind of cool junk I could hang in the tank behind that big stump. But the stump is only going to be around as long as this scape, in all liklihood - call it a year or so. I'm looking for a semi-permanent solution.

So I'm trying to find a solution that will work with no equipment in the tank - tough I know!