solenoid for automated zooplankton feeding

[dave w]

Hey folks,

 

I am trying to automate a live zooplankton dosing system. I found the below solenoid on ebay and it's combination of nylon and stainless gives me hope that it is saltwater safe. Normal home sprinkler oil/water/gas solenoids typically need at least 15 psi of line pressure to open, this one needs 3 psi. Do I remember correctly that each foot of vertical water pressure (head) is one half of a psi? So this means my zooplankton water tube needs to be at least 6 feet high to operate this solenoid, right? And because it's 110V AC current, can't this solenoid plug straight into the power supply of an outlet from a controller? Thanks in advance for the help, I know just enough plumbing to do dangerous and idiotic things.

 

Nylon Solenoid Valve with Barbs for 5/8" Hose

Brand New with Six-Month Replacement Warranty

Stainless steel clamps and terminal connectors included

 

Voltage

110-120 V ACCurrent

100 mA

Operation Mode

NC (Normally Closed)

Operation Type

Diaphragm Valve

Barb Size

5/8" Hose

Valve Body

Nylon

Seal Material

NBR (Buna-N)

Working Media

Water, Air, Natural Gas,

Low Viscosity Fluid, etc.Media Temperature Range

25

[OldReefer]

Here is another one on EBay designed for gravity feed.

 

I have bought from this vendor several times.

 

 

1/2" Gravity Feed Electric Solenoid Valve DDB-CD-12VDC

 

 

 

http://www.ebay.com/itm/1-2-Gravity-Feed-Electric-Solenoid-Valve-DDB-CD-12VDC-/300653378588?pt=LH_DefaultDomain_0&hash=item4600567c1c#ht_2485wt_791

[Origami]

A foot of water is roughtly 1/2 psi, yes.

 

The way I read it, you need 3 psi to overcome the diaphragm back pressure.

[dave w]

Here is another one on EBay designed for gravity feed.

 

I have bought from this vendor several times.

 

 

1/2" Gravity Feed Electric Solenoid Valve DDB-CD-12VDC

 

 

 

http://www.ebay.com/...c#ht_2485wt_791

 

Many thanks Bill. I looked through their valves and ordered one, the same type as you show above but 120 volts AC instead of 12 volts DC. That way my electronic stupidity doesn't have to figure out how to wire an AC/DC converter up to the controller. Please let me know if I did OK or messed up. I ordered one to mess around with and will eventually order half a dozen. If in your experience DC is any easier than AC, just let me know.

[dave w]

Oh, and one other thing. What is the typical number of seconds or nanoseconds of response time on these valves? Draining a 6' tube at 3 psi would probably be quick, so I'll probably need to time the drain event with a stopwatch before programming the controller on how many seconds for the solenoid to be open. Right?

[OldReefer]

Dave,

 

120 vac will be easier to wire and probably a little more precise to control. I just tend to keep that sort of voltage away from the tank. You might want to restrict the tube own a little bit to make timing less critical. An Apex can be pretty precise using the OSC command and the low current outlets at positions 4 & 8 on an EB8.

 

This looks like lots of fun. Keep us posted!

[OldReefer]

Dave,

 

You've got me thinking. What if you used the solenoid to dump a pre- measured amount of water into the plankton container, and the let the plankton container overflow into the display tank?

 

You could have a 1 gallon bucket ( or size of your choice) conitnously being filled with a trickle of tank water and overflowing back into the display. Just a little 1/4" John Guest fitting tapped into a return line would do the trick. Another little fitting tapped into the bucket at the desired max water level would let excess water flow harmlessly back into the display between meals.

 

At dinner time, the solenoid could dump the water from the bucket into the plankton tank, which in turn would overflow into the display. The solenoid could stay open an extra 30 seconds and it would make almost no difference. The amount of plankton could be fine tuned by tweaking the overflow level of the bucket.

 

Just a thought. I have built a ton of crap that didn't work...

[dave w]

Dave,

 

You've got me thinking. What if you used the solenoid to dump a pre- measured amount of water into the plankton container, and the let the plankton container overflow into the display tank?

 

You could have a 1 gallon bucket ( or size of your choice) conitnously being filled with a trickle of tank water and overflowing back into the display. Just a little 1/4" John Guest fitting tapped into a return line would do the trick. Another little fitting tapped into the bucket at the desired max water level would let excess water flow harmlessly back into the display between meals.

 

At dinner time, the solenoid could dump the water from the bucket into the plankton tank, which in turn would overflow into the display. The solenoid could stay open an extra 30 seconds and it would make almost no difference. The amount of plankton could be fine tuned by tweaking the overflow level of the bucket.

 

Just a thought. I have built a ton of crap that didn't work...

 

Bill, I like your ideas and we are thinking along the same lines. My idea was to pump zooplankton to a bucket. A controller and aqualifter/gravity solenoid dump greenwater into the bucket for 6 hours for zooplankton enrichment. After enrichment, #1 of two solenoids at the bottom of the bucket opens to dump enriched zooplankton into the display, just as you say. After the bucket is empty, solenoid #1 closes, solenoid #2 opens, and an upside down shrub sprinkler at the top of the bucket sprays in house freshwater to clean the bucket.

 

Solenoid #2 drains to the sewer and is flush with the bottom of the bucket, solenoid #1 has a little riser in it so the bottom half inch of crud doesn't go to the display. Crud should wash down the drain when solenoid #2 opens.

 

Although this is clear in my head it's likely that my narrative isn't so clear. But you've probably failed at enough projects to follow me. I've also screwed up a ton of DIY stuff, which is why I try to keep things as simple and automatic as possible.

 

Your tank overflow idea is just as good as the 2 solenoid idea and it is simpler. I like it because the crud that builds up on the bottom of a zooplankton tank isn't what you want in your display tank and an overflow system would leave the heavy poop at the bottom. But I'd like to avoid hand cleaning the bucket and I hope the second solenoid to drain and a full pressure sprinkler solenoid controlling the freshwater cleaning system automates the cleaning.

 

I hope the pressure of the fresh water sprinkler is sufficient to wash out the bottom poop. If this method doesn't adequately clean the bucket then hand cleaning may be needed which I hate. What I could really use is a conical bucket to facilitate crud removal. I'll probably have to make one from fiberglass if a bucket accumulates crud on the bottom.

 

A couple more thoughts. Dump the zooplankton after dark so the corals can feed, use veggie juice in a fridge to replace phyto. I've even heard of some people dumping their skimmate into the copepod tank to feed pods. If it takes 6 hours to gut load rotifers and artemia, then why not use 4 buckets for each zooplankton and just feed the tank 24 hours? I just read Calfo's book on coral propagation and he insists that corals grow fastest fed zooplankton in sunlight systems. That makes sense to me.

 

I'll let you know how it goes (how big the failure turns out to be).

Edited February 27, 2012 by dave w

[dave w]

A foot of water is roughtly 1/2 psi, yes.

 

The way I read it, you need 3 psi to overcome the diaphragm back pressure.

 

 

Tom, sorry I overlooked your post in the excitement to trade ideas with Bill after he steered me toward zero psi valves. I don't mind making the enrichment tubes 6' high to overcome the back pressure and a little pressure could actually make a better food delivery system. But I'm using a diaphragm pump to send concentrated zooplankton from their reservoirs to the top of the enrichment tube. From the zoo reservoir to the top of the enrichment tube is about 11' of vertical rise. Although a diaphragm pump (like a Jabsco) will pump this head, I'd like to mimize the amount of water left standing in the pipe for 6 hours between cycles. I'm afraid the lack of oxygen will kill zooplankters left in the line between the pump and the top of the enrichment tube.

 

So there are a couple of benefits to using shorter enrichment tubes. It is less wear and tear on the pump if I lower the vertical head from 11' to about 8', and there is less dead water in between cycles if the pipe is 3' shorter. Another possibility to reduce the amount of dead water is to decrease pipe diameter between the pump and the tube, although this makes the pump work harder.

 

Sorry if this isn't a clear explanation, I hope you understand and I hope you have some more ideas.

[OldReefer]

Dave,

 

I underestimated your level of commitment.

 

I am reminded that one should never challenge a man building a 3,000 gallon reef tank to a crazy contest. I like the way you roll.

 

I get where you are headed, but it will sure be complicated to get all the timing right. The enriching concept makes it all a notch harder. You might consider enriching the whole population and taking a bit off the top. The trouble of course is getting rid of the nasty stuff in the bottom.

 

We should try to lure Dan and Justin from Avast onto this thread. I know Justin has been noodling around with plankton dosing ideas for years, and Dan actually builds stuff that works.

[dave w]

Bill, I'm not sure if crazy or stupid would better describe a big tank builder. But plankton dosing the corals really intrigues me. Rotifers aren't photopositive but your skimming idea is a good one to try on artemia and copepods. Perhaps a light turns on at the top of the tube and only the top foot of water drains to the tank.

 

I know these will be famous last words, but timing seems to be the easy part if I buy that $89 expansion thingy that allows a controller and relays to work up to 64 outlets.

 

Because the state of the art has evolved light years since my last programming class in 1982, my proposed schedule is very crude:

 

1. After 6 hours in the tube, say 6:00 p.m., solenoid #1 (an inch off the bottom) opens and enriched plankton gravity drains to the display tank for five minutes.

2. At 6:05 solenoid #1 closes, assuming that 5 minutes was sufficient to drain the tube.

3. At 6:06 solenoid #2 (flush to the bottom) opens to drain off the bottom inch of crud water and also solenoid #3 (at the top of the tube) opens to spray pressurized fresh water to clean the tube.

4. At 6:09, freshwater solenoid #3 closes.

5. At 6:10 the bottom solenoid #2 closes.

6. At 6:11 the diaphragm pump turns on for whatever time is necessary to refill the tube, say, 4 minutes. Your advice of an overflow fitting near the top of the tube is well taken if the pump overfills.

7. At 6:15, your wonderful gravity feed solenoid from the greenwater reservoir (solenoid #4) comes on for, say, 10 seconds to dose a quart of phyto to the tube.

8. Wait 5 hours 45 minutes and repeat.

 

I know it will be a lot harder and more complicated that what I've described. But the reason I like controllers and solenoids is because stupid people can operate them, and it seems that a little experimentation could make this stupid proof even for me.

 

This setup requires greenwater above the enrichment tube and enrichment tube above the display tank. If I substitute V-8 juice for greenwater (a la Martin Moe), I'd need a small fridge above the enrichment tube to hold veggie juice and beer.

 

After I build a prototype, come over some weekend morning to suggest improvements and kick it around, nothing works the first few tries. One disadvantage is that the enriched water is dirty and it's best to net out zooplankton for the tank and leave the culture water behind. This would be ideal but I think a large tank can cope with a few gallons of dirty water every 6 hours. I don't know Dan but Justin is smart and very well experienced in aquaculture. He gives good advice.

Edited February 28, 2012 by dave w