Large tank project Advice

[Herpervet]

Nonot: I think I understand what your saying. Just T off the line with the pump with valves so I can pump the cistern dry.

That shouldn't be a problem to add in. I hope to never have to pump it dry.

If you look at the cistern note all the ribs it has built in. Those are hollow and communicate with the inside so when you look at the bottom there are parallell, two inch deep channels in the bottom.

Sediments will collect in those grooves and I plan on creating a sort of vaccum cleaner by attaching a large piece of pvc to the inlet of a submersible pump and then attach the outlet of the pump to a trashcan with filter media and an outlet in the bottom that would flow back to the cistern.

I would just stand over the cistern and vaccum the grooves and do the clean-up.

The other thing is that the manufacturer recommends to never pump it below 25% full because the weight of the surrounding earth can collapse the cistern.

Hell I could even plumb a "T" into one of the pipes into the cistern and attach the outlet for this trashcan filter, and let the water flow back via that route.


I will draw a pic of this I think it will work pretty slick.

Thanks for all the help Nonot and H2ENG!
:thumbsup:

 

[Herpervet]

actually I should correct my above post. I will need to design a angle on the handle to reach a good portion of the cistern to do the vaccuming job I mentioned.

 

[Herpervet]

Slowly but surely. Two 1.5 inch bulkheads on each side of the cistern. We decided on this placement rather than the standard spots located toward the ends because it would allow easier access without taking a swim

I was struggling on how to plumb the float valve in the cistern and I think I have a solution.

I will post a diagram and a pic of it in a day or two.

 

[Herpervet]

The coupling allows me to take off the float to change it out or clean it.

In addition I can drop the cistern level (i.e. the level at which the top off is activated) by lengthening the vertical pvc pipe before the elbow.

The endcap is threaded so it can be unscrewed for cleaning or changing the valve out.

 

[Herpervet]

H20Eng et. al.

Anyone have a good source for Hayward three-way actuated valves?

I found a 1.5 inch valve that is listed for about $380. Also I need to look at temp. controllers to operate this baby.

 

[NRA4EVR]

www.customaquatic.com is where i got my three way.

 

[Herpervet]

thanks. Any thoughts on a reliable controller? i.e. brand etc.

 

[H20ENG]

Go with the dual stage Ranco. Digital, 1 degree deadband, controls heaters AND chillers, and bulletproof!

 

[Herpervet]

Would this work? The air tubing would have to be fished through the 1" pvc and then connected to the pressure sensor in the cistern and the solenoid on the other end.

What kind of fitting would be needed to seal around the airline tubing where it exits the pvc in the cistern?

Here are a couple of progress pics:

Note the floor drain plumbing is also done. I thought about plumbing to it for a clean way to drain the tank but if the system ever got plugged there would be risk of sewer water backing up into the cistern. A chance I wasn't willing to take.:

 

[Herpervet]

Actually, it makes a lot more sense to put the air line for the pressure controlled top-off through the vent tube. No need to worry about a tight seal that way.

 

[Herpervet]

Would this configuration for the bubble trap portion of the sump work?
This configuration would allow for increased or decreased space between the baffles if needed depending on flow.

Obviously these wouldn't be water tight and a small amount of water might make its way around the baffles, but the idea is simply to divert water flow which this should accomplish I think.

 

[H20ENG]

Those baffles will work. I usually use longitudinal baffles. This gives you a much longer detention time for the bubbles to come out of suspension.

What is the airline for in the cistern? Topoff switch? It seems the mech float would take care of it.

 

[Herpervet]

Yes the airline is for the pressure activated level controller but I decided it was much simpler to run it through the vent line instead.


I just like the idea of having redundency so that you are not relying on only one float to prevent a disaster.

Perhaps I am too uptight.

 

[Herpervet]

Those baffles will work. I usually use longitudinal baffles. This gives you a much longer detention time for the bubbles to come out of suspension.

I think I have seen it done this way but help me out. I can't quite visualize how it is done.

You only have two edges of the baffle secured to the glass if you do it this way right?

 

[H20ENG]

Top view

 

[H20ENG]

"Perhaps I am too uptight."

Nope. redundancy is a good thing

 

[Herpervet]

Top view

Ok. That is what I thought.

You just shot down my adjustable baffle idea

So what kind of spacing and how many baffles for 2 to 4000 gph flow through the sump?

I plan on using a sequence hammerhead (5800 gph) for the main loop and something much smaller for the cistern loop but I am still open on this subject.

Two closed loops with hammerheads for circulation.

 

[H20ENG]

Wide enough to slow the flow down to let the bubbles rise out. anything less than than 1'/sec velocity will let them out (IIRC). Slower the better.
I'd go for maybe 8" wide raceways. You could put a vertical baffle at the end to adjust the height.

 

[Herpervet]

Thanks AGAIN!

I will start drawing up a design on this next. I will probably DIY this part out of glass. I have worked some with acrylic but the more I read the more I worry.

Glass, on the otherhand, is simple and I have a good source that charges by the square foot so the cuts don't cost anything.

Any favorite acrylic techniques? I am not all that handy with power tools, but I have gotten good at the score and snap technique with acrylic.

I have read about using 25g needles to leave a gap for a good joint.

Which weldon product do you prefer?

 

[H20ENG]

If you are good with glass, go for it. I like acrylic because its so versatile. You can bend it, drill it, cut it glue with normal tools. I have learned to work with it over the years, but the threads on here about acrylic spell it all out real well- if youve got 2 weeks to devote to reading through it all!
Basically, I use a tablesaw to cut about 1/8" oversized pieces. I use the router table to shave 1/16" off each side to get the final dimension. Remember you only have to route the sides to be glued. any pieces that will be flush routed later, dont waste the time. DO cut them about 1/8" oversize, though, so you have a small lip to drag the needle on. Its too messy to try to glue a piece right at the edge, and you'll end up gluing it to the table. (Hmmf, learned that the hard way years ago...)
Score and snap wont leave a good edge for gluing.
I made some glue jigs to hold the pieces at 90 deg- this helps. I think there is still a pic in my gallery. I use wire instead of pins, but thats just what I have laying around.
I use weldon 4 for all my stuff.
HTH