Please, Review My "tidal System" Plans

[Dave Legacy]

Hi Guys,

I felt this belongs in the brackish thread because who else is more likely to make a tidal system for thier tanks? So I decided afterall that I want to do a Tidal System for my 200G since the mudskippers/crabs will like it and more importantly Red Mangroves wont grow prop roots if a tide is not present. Today I went back and reviewed a thread I had made about a possible wavemaker and used some information that CFC gave me to try to setup a plan for a Tidal System. It's pretty much all of CFC's plan with a very slight Dave Legacy twist.

Here's the diagram:

The idea is that I'll have a constant drip coming from the Display tank into a Reservoir through an airline siphon, just like when you drip acclimate. The airline will be around 6" from the substrate just to be sure that all the water can't be drained out of the tank at any time if something should fail. The water would drip slowly for a 6 hour period hopefully dropping the water line maybe 6"+. Then a pump in the reservoir will fire up and return the water into the tank at a drip rate of 2x the siphon rate to replace the water that is driping out while adding water at the same time to bring the water level back up to it's original starting point. After the 6hr refill period the pump will shut down and the water will be able to siphon as usual without competing with the pump.

Things that I didn't do diagrams of is I think I might need to use a HOB filter in the reservoir to keep the water fresh, I don't know if it will get stale down there or not. The other thing is I want to use a ball valve on the return line to the Display Tank to keep the drip regulated and slow down the return but I wanted to know if it was safe to do that or if it would put too much strain on the pump. Oh, and will my reservoir need to be heated?

I could use some suggestions, any one have any ideas?
Thanks in Advance,
Dave

 

[andywg]

I would be worried about the syphon breaking on the air line and the pump draining the sump dry. you can almost guarrentee that the drip/refill rates will not be the same and will cause the system to get out of whack. Plus, tides aren't really a drip, the tide tends to rush in and out rather than drip fill. If you had it drain in a matter of 2 hours and then fill up in 2 hours a few hours later it might be better.

You could restrict the flow of the return pump a little with a ball valve, though if it is going to make a large difference you will be better off putting the return to a tee, that way the flow you don't want can return to the sump and will prevent the water from sitting stagnant and will stop there being any unnecessary strain on the pump.

But I do like the thinking of the plan.

 

[Dave Legacy]

I've been getting some good responses and I've revised some of my plan. I think I'll try to track down a mechanically operated ball valve from a garden drip system to open the intake by a timer. When 35g of water have bled into the reservoir a float switch will close the intake flow and thus end the Low Tide Phase. I expect the Tide Changes to take about 2 hours and let the water sit in the reservoir for about 4 hours. This will make sure the tides are completed before they start a new cycle.

6 Hours after the Low Tide Phase begins a timer will start up a pump in the reservoir to begin the High Tide Phase. This will return water at maybe 15gph back into the Display tank until the water line has returned to about 14" the second float switch is triggered and the pump is shut off. Then the cycle starts over.

Here's a mock up of the schedule:

5:00am - Low Tide Phase begins/Intake Starts
7:00am - Low Tide Met/35G in Reservoir/Intake Stops/Steady Water Level for 2hrs
11:00am - Low Tide Ends/Return Pump Starts/High Tide Phase Begins
1:00pm - High Tide Met/35G Back in Display/Return Stops/Steady Water Level for 2hrs
4:00pm - High Tide Ends/Intake Starts/Low Tide Phase Begins
6:00pm - Low Tide Met/35G in Reservoir/Steady Water Level for 2hrs
10:00pm - Low Tide Ends/Return Pump Starts/High Tide Phase Begins
12:00am - High Tide Met/35G Back in Display/Return Stops/Steady Water Level for 2hrs
4:00am - High Tide Ends/Intake Starts/Low Tide Phase Begins

So how does this work, is it a better system?

 

[Dave Legacy]

I'm having a ton of trouble finding automatic ball valves to use with the intake feed from the display tank into the reservoir. Even if I did find them I wonder if the line would be able to hold the vacuum and continue to siphon when the valve was opened. Might I need to have to pump operate the intake? Can a pump be used to suck rather than push?

Aquarium Systens makes a Micro Jet 320 Pump that has dimensions of 2" tall x 1.5" thick that can do 32, 49, or 73gph, with a max head of 15". What does Max Head mean? I'm building some land masses out of styrofoam and concrete that could have some sheer faces. I could cut a compartment into one of them and make a vent on the side of the embankment with a grate over it that would take in water and then pump the water up the tubing over the top and back down into the reservoir.

Might this be a more logical way of doing this?

 

[Little Fish]

Dave, this is some engineering project you're planning! Max head is the maximum height a pump can pump water upwards (against gravity). Since you are thinking about draining down, this number is not important. Most of the pumps and power heads I used allow connection of both intake and output hoses so I guess it doesn’t matter if you use it to drain instead of pump.

I think the biggest problem with a two-pump system in the reservoir is to maintain correct water level. Your idea of using a timer to drive the drain pump should work but we don’t have a mechanism to control the amount of water in the reservoir. The return pump might run dry if you only use a timer. You might need a float switch and a relay working in tandem with the timer. If your reservoir is big enough and you don't mind a rapid refill, a small building sump pump is a self contain package. The more I think about your project the more technical difficulties popped in my head. I admire you for taking on a project that complicated. Let us know how it turns out.

 

[Dave Legacy]

Little Fish,

Haha! I've been through so many plans so far, I just haven't been posting them. At least one float switch is a must, I've found one made my Fishbowl Innovations that I like. The more complicated my design got the more I realized it didn't have to be. I'm going to experiment with a "Back Siphon System". Water will pump out of a reservoir for 6 hours controlled by a ball-valve and a T-fitting to relieve pressure. I'll setup a float switch in the reservoir to cut-off the pump if the water level gets too low... this should prevent the pump from running dry. I wont need a float switch in the tank because the reservoir wont be big enough to overflow the tank.

Back on track. The Pump is now shut off. It will naturally start a back-siphon and drain all the water back into the reservoir, hopefully at the same rate. The siphon wont be able to drain the entire display tank because the feed/return hose will be setup at the designated "Low Tide" line.

If I find this system to be too inaccurate even after all the fine tuning, I'll just build upon that system since those are all parts I would need for the more complicated designs. Thanks for the ideas and I'll keep you all posted.

Dave, this is some engineering project you're planning! Max head is the maximum height a pump can pump water upwards (against gravity). Since you are thinking about draining down, this number is not important. Most of the pumps and power heads I used allow connection of both intake and output hoses so I guess it doesn’t matter if you use it to drain instead of pump.

I think the biggest problem with a two-pump system in the reservoir is to maintain correct water level. Your idea of using a timer to drive the drain pump should work but we don’t have a mechanism to control the amount of water in the reservoir. The return pump might run dry if you only use a timer. You might need a float switch and a relay working in tandem with the timer. If your reservoir is big enough and you don't mind a rapid refill, a small building sump pump is a self contain package. The more I think about your project the more technical difficulties popped in my head. I admire you for taking on a project that complicated. Let us know how it turns out.