Rotifer Tower

[dave willmore]

The designer's creed is K.I.S.S (Keep It Simple Stupid). I have gotten off of the rails on this one"¦just because I thought that it would be great fun and almost within reach. I would prefer the natural approach but I couldn't pass it up.

You took a chance that could have worked nicely. Natural systems are simple but a $30 arduino will automate to save many hours of maintenance, so your try is a good one. I lean toward water based solutions rather than mechanical ones because few things are easier to automate than pumps and timers.

You have made me think of doing rotifer reactors like yours but with a twist. With your limited space and light you use powdered phyto, but I have plenty of light and water. My angle would be to filter dirty shrimp water and feed it to nannochloropsis bags which overflow to rotifer bags which overflow to the corals. Higher water volumes and lower densities tend to give continuous cultures that last longer between crashes. What do you think?

We share the same problem, how to automate? I'm thinking of connecting a pH or photocell to the arduino so when algae growth gets dark green or brown and the pH climbs, the sensors tell the controller to pump clear nutrient water with lower pH until the sensors detect a clearer bag. Simple in concept, but at this point I don't know how sensitive the sensors will be. pH sensors can clog with biofilm, but photocell receptors can be placed outside the clear culture bag and stay clean.

If sensors are not accurate, they only need to kick on the pump to feed 5 gallons of clear water into a 25 gallon culture, without using the feedback.

This works for me because the sun is free. Would it work for you? You would save the cost of dried phyto and nutrient export, but you would increase your electric bill for the algae lights.

 

[herring_fish]

I have a sun room in the back of the house and my wife has given me clearance to mess with that stuff. Unfortunately, I am afraid to mess with phyto yet/ever. From what I have read, frequent crashes is something you can only manage with lots of cleaning, not eliminate. I am sure that with more experimentation, there will be methods that will be less finicky. That is why I am interested in following what you will be doing.
I have read this basic idea a few times but I haven't seen anyone put in the time and energy to actually try it. If half of it works the it will be worth it. I am getting more and more confident that my experiment will work but I am afraid of adding a whole new discipline to what I am already doing. I bit off a leg of that elephant and that is all that I can chew write now.
As for the specifics, I don't know much about any of this stuff and when I started, I knew nothing about any of it. I have learned just enough to get past the next phase of what I need to get done. Then I promptly forget half of it, like after a final exam.
I found that Reed's liquid food is much easier to regulate accurately, at least until I get some experience under my belt. I have thought about using sensors to check the water quality in the tubes. The Arduino would be great for that. I haven't done any research on that yet.
The guys at Reed say that after oxygen, ammonia is the limiting factor for when searching for that upper limit of rotifer population via higher feeding levels. I looked for an ammonia sensor but didn't see much at a reasonable price. pH is an indirect method of finding that crash point. I'm sure that there are other ways to measure when things are about to go bad but an controller would work quite will.
I guess with phyto, you have to look for other stuff like bacteria. That being said, density is definitely something that needs to be managed. I just don't know the what, when and where to look yet.
It looks like there have been over 4 thousand visits to this thread and I hope that more people will stop long enough to give their knowledge, opinion, point of view and or experiences, no matter how insignificant, contradictory or potentially controversial it might appear. Every little bit can help tune these wild ideas.

 

[dave willmore]

I sympathize with all your trials and tribulations, I've had them since 1984 but please don't be afraid of phyto. Although there have been a thousand culture crashes most of them were beginner mistakes like contaminated containers, contaminated air going through the air pump, contaminated airlines, uncovered cultures, rotifer cysts on the hands that worked on the algae culture....

Please look at phyto culture as something that requires 4 biology classes and failures came from those with one bio class who thought uncovered culture aquariums and unfiltered air would be OK. Think through the process of clean air and containers and you will understand that those who claim that phyto is difficult just had poor cleaning skills. Nannochloropsis is falling off a log easy.
With your degree of scientific and mechanical experience phyto would be a snap.

OK, enough said, I'll get off my soap box.

The folks are Reed are right about dissolved oxygen and ammonia levels but I'd culture at far lower densities than the pros. High density has many more problems than low density cultures which can be semi-continuous. Don't worry about sterility, all phyto cultures have low level contaminants which is actually a good thing and creates B vitamins. Just remember that in the presence of light and UV, phyto outcompetes bacteria by many times and a contaminated culture is normal.

When I wrote about pH and photovoltaic sensors I didn't mean for the rotifer tank, I meant them for the phyto bags. I see the rotifer bags as a flow through system. If I get high ammonia levels I'll simply dump rotifers into the algae refugium before flowing to the corals.

And look on the bright side of things. When a culture crashes, you haven't lost a tank of rotifers, you've gained a tank of ciliates! Feed algae to the ciliates until you get tired of them but your corals love ciliates too.

So keep going. Eventually the hobby will realize that live plankton is far superior to dead foods. They just don't yet know how to pump and filter water without removing the very plankton the animals need to thrive. When they come around, your type of project is the type of solution that is needed.

 

[herring_fish]

So when are you going to start and what will be the first thing that you will build?

 

[dave willmore]

I've been going for a year now, the greenhouse room has taken that long. The tank frame is stainless steel. and I just put on the first layer of fiberglass, a 4'x8' sheet product called FRP. The second layer will be a premade roll of 5 oz fiberglass and resin, which will be attached to the first layer with West 105 epoxy. Then after much taping of corners the third layer will be 18 oz fiberglass cloth. I will post a picture, only one half of the display fits in the frame at once, because the main tank is 20' long. There are two legs that come off the sides that are 11' long making it into a horseshoe, then algae refugium and connector tubes turn it into a circular doughnut. A square doughnut is more apt. I'll have phyto shelves on the back and up above.

Your rotifer tower really got me thinking to go this direction, I had already planned brine shrimp and copepods. Have you ever read Frank Hoff/Terry Snell's book on plankton culture? (As far as I'm concerned it is the plankton bible). Anyway, after reading your tower description I remembered a section in their book where rotifer culture on detritus showed decent growth rates so you inspired me.

You are close enough to see the tank one day, we are about 5 hours apart. Let me know when you come up to the DC area.

 

[seafarm]

To grow live microalgae you are going to add high levels of nitrates and phosphates to the algae culture, and will therefore constantly be injecting the system with a new stream of N&P.

If you feed the rotifers with concentrated microalgae, the majority of N&P have been removed through centifugal harvesting, leaving just the food value inside the microalgae cells. This will result in a much lower introduction of N&P into the system, and less maintenance of removing them from your system.

 

[synapse2]

Want to make some thing simillar

Want to make some thing simillar

Thinks have slowed down because I have been very busy.

A new problem that I have is that when I turn of the power to the motor, the extender falls down into the tube because there is very little friction on the slide. Without power, the motor offers very little resistance. The aluminum slide is about 16 inches long and has a plastic gear rack attached to it. The bracket and clips for the ¼ inch feeding tube(s) weigh almost nothing.

(This rack and pinion extender is mounted vertically.
Please look at earlier post for assembly picture to see location.)

Should I add some Teflon with a spring behind it for a friction stop or something else? I could get some of it (perhaps in a dowel shape) and put it in a tube with the spring and attach that to the carriage.

Another thing that I could do is to try to find a solenoid type brake. Since I have an Arduino controller, it would just require a few extra lines of code. The down side is that I would have to add a couple more wires that go to the carriage. I was hoping to limit it to two wires. That makes it easier to run without e-chain.

Can you think of anything that would work better?

Hey, where did you get the motor, the gears and the slide. I want to make some thing simillar


Thanks,

 

[dave willmore]

To grow live microalgae you are going to add high levels of nitrates and phosphates to the algae culture, and will therefore constantly be injecting the system with a new stream of N&P.

If you feed the rotifers with concentrated microalgae, the majority of N&P have been removed through centifugal harvesting, leaving just the food value inside the microalgae cells. This will result in a much lower introduction of N&P into the system, and less maintenance of removing them from your system.

Randy, you're quite right, but we're talking about two different animals. The centrifuge removes algal culture water with high N&P but the paste itself contains N&P so the tank accumulates nutrients.

Growing phyto from display tank N&P after detritus has been converted by brine shrimp is a different approach. Turning waste into plankton doesn't increase nutrient levels, it actually lowers them as plankton is converted into more coral tissue. Just as coral growth also absorbs some of the N&P from algal paste.

I don't mean this as criticism. Paste is a wonderful product. Probably only large systems with lots of light have the luxury of nutrient recyling through detrivores and live phyto.

I think a high biomass of live plankton flowing through the tank is a different step forward. Both philosophies represent progress. I hope this doesn't come off as preachy, I really do like algal paste products!

 

[dave willmore]

I found that Reed's liquid food is much easier to regulate accurately, at least until I get some experience under my belt.... I have thought about using sensors to check the water quality in the tubes.

It looks like there have been over 4 thousand visits to this thread and I hope that more people will stop long enough to give their knowledge.... and wild ideas.

Here's a wild idea. Dispense the algae paste into a water bucket with an autofeeder (or auger powered by an analog clock?) for measured paste addition. Use an airstone in the bucket for algae suspension and program a relay to power a Toms aqualifter to dose phyto from the bucket into each rotifer reactor.

You'll have a simple liquid doser from off the shelf components, rather than your brilliant mechanical mover. Also consider the $13 dosing pumps to flow rotifers to your dump tray if you don't use gravity. You could also use a float valve in the top of the reactor tube to power the aqualifter and match the input of algae water to the output of rotifer water.

To go a step further, consider dosing ground up detritus straight to the rotifers and eliminate the algae middleman. Powerheads at one end of your display tank push detritus to the opposite end where a small sump pump is sunk down below sand level. Detritus is loose enough to flow to the lowest point if your water flow is appropriate. The sump pump both grinds the detritus and sends regular doses of it to the rotifer reactor according to your controller. The reactor can be as simple as a plastic trash bucket. If its above the tank put in an air gap to prevent back siphoning.

You'll be combining automatic tank cleaning with auto plankton. Who cares if it's less efficient, use two or three trash buckets instead of one.

The theory is to use large water volumes of relatively low nutrients for continuous cultures. The remarkable thing about critters is their ability to concentrate nutrients from surrounding waters.

I'd guess you could try for 50% to 100% daily reactor turnover. Whatever you decide is an appropriate daily dilution rate is what dictates how often the sump pump operates, and you'd want the two flow rates to match.

Again, a float valve in the reactor could power sump pump -- let your imagination run wild. (oops, too much caffeine for lunch!)

I'll look for the Hoff/Snell reference and send you the poop (couldn't resist the pun!) on using detritus for food. My memory is that researchers fed rotifers a continual flow of brownwater from the Mississippi. Although it probably had high numbers of diatoms it was probably also high in sediments, nutrients and pollutants. This is what I'm going to do with brine shrimp (less the polluntants). Consider both.

 

[herring_fish]

What you are doing is amazing. I look forward to seeing it develop. Please take lots of pictures.

 

[herring_fish]

synapse2,

I ready hesitate to give out any spec.(s) for what I did because nothing worked right out of the box but here goes.

If you don't already know your way around this stuff, you are looking for a world of hurt. I felt the pain! I made it work by hook and by crook so I don't vouch for any of the products or for my design.


Rack and Pinion Pocket Door System I wanted to use plastic so that that it is light.
http://www.schockmetal.com/images/slides/datasheet/RPPD Data Sheet 1-09-08 E.pdf


Pololu Robotics & Electronics
Stepper Motor: Bipolar, 200 Steps/Rev, 28x32mm, 3.8V, 670mA http://www.pololu.com/catalog/product/1205

A4983 Stepper Motor Driver Carrier with Voltage Regulators
http://www.schockmetal.com/images/slides/datasheet/RPPD Data Sheet 1-09-08 E.pdf

Custom Bushing
http://asaherring.com/reef/tower/BushingDWG.jpg
The Pinion and the motor did not match so I had to have a custom made bushing made. It cost about 10 bucks but could have been much more. The set screw might not be needed. Loctite MIGHT be enough. I don't know.

I got all this working together only by asking a lot of questions on forums. I am not a good resource for the details on how I made it run. I'm dyslexic so I have to be very interested to compose posts. Documenting the details of what I did would just take too long.

When I got the individual components working on the bench, I moved on to the next issue on my list. Over time, I disconnected the electronic parts for one reason or another, without taking good notes beforehand. When I was ready to add the extension cables, I had to re-figure out how to hook it back up again. I am a design guy not an implementation guy. Shoot, I hardly remember what I did last night.

I got most of my information for this project, included much needed tutorials from some of the following websites and forums:

http://www.ladyada.net/learn/arduino
http://arduino.cc/en/Tutorial/HomePage
http://www.arduino.cc/forum
http://www.CNCzone.com
http://forum.sparkfun.com
http://www.robotshop.com/forum
http://www.forums.adafruit.com
http://www.electro-tech-online.com/microcontrollers
http://forums.reprap.org
http://forum.pololu.com
http://www.practicalmaker.com This is web site of a guy that makes controller for most aspects of the aquarium system and uses an innovative design and programming approach.

Good Luck

 

[dave willmore]

What you are doing is amazing. I look forward to seeing it develop. Please take lots of pictures.

Flattery will get you everywhere! Next time you come north on I-95 you should stop and see it and see how many beers it takes to figure it out.

Actually you are only 5 hours away and I may make you come up to help finish it. Just kidding, it should be ready in another few months.

 

[dave willmore]

Pololu Robotics & Electronics
Stepper Motor: Bipolar, 200 Steps/Rev, 28x32mm, 3.8V, 670mA http://www.pololu.com/catalog/product/1205

That stepper motor looks like a good product. Do you think it would move a venetian blind?

To keep plankton alive I am moving water with slow turning props instead of pumps and the 500 gallon algae refugium is at the same level as the display tank, wrapped around perimeter of the sunroom. The algae fuge will be on reverse daylight photosynthesis to keep up tank pH and dissolved oxygen levels at night.

I would like to roll down a venetian blind before the algae lights turn on so the sleeping fish aren't disturbed, then roll it up in the morning so the fuge can get sunlight. Do you think this motor is powerful enough?

I only ask because I am a total mechanical idiot.:strange: Thanks for your help.

 

[TheFishMan65]

Dave don't move the blind. Just turn the louvres to get more or less light. This will allow more even dimming and brightening rather than shadowing a portion of the tank.

Plus you will use less energy which you are very conscious of.

 

[herring_fish]

It might work but you have a world of motors to choose from. I was just looking to the lightest motor that could find. A lot of these smaller motors are pretty cheap. You could also look at servos. You can get both types of motors with gear drives build it.

 

[TheFishMan65]

I would also recommend looking into stepper motors. A little more trouble to drive and probably buy, but they have some real advantage IMHO. They are driven in steps so the controller knows exactly how far the motor moved. I am familiar with 200 steps per rotation and some driver support microsteps of 16 so that would make 3200 per rotation. They could then be geared for either finer control. The rate of thee step contols the rotation speed so you can get very accurate rotations per second.

 

[dave willmore]

Dave don't move the blind. Just turn the louvres to get more or less light. This will allow more even dimming and brightening rather than shadowing a portion of the tank.

Plus you will use less energy which you are very conscious of.

Louvres sound like another valid approach. I have a bias toward a blind which rolls all the way down or all the way up, whereas it seems the louvres will have shadows unless they turn with the sun and seasons. But I promise to be open to both.

And you're right that I'm very conscious of energy use. There are two reasons for this. One, I was 12 hen the 1973 oil embargo hit and energy became ingrained into the consciousness of an impressionable teen.

Two, if you look at the long term, electricity costs will be more over 10 or 20 years than the tank and livestock combined. Many serious reefers are probably embarrassed to admit their electric bills and I would like to influence a more conscious trend in the hobby. Now I've probably gotten everyone mad at me.

 

[herring_fish]

I had to use a better gauge of wire to get power to the second motor which is 8 feet away, down the cables.

Right now, I am working on building the cables. I am using cable ties to insure that the three cables make a straight line so that they will roll over as it moves down the rail.

Also:
I didn't include the slide that the rack is attached to so here is the lick to that. I just use some small screws that I bought at the hardware store put them together.
http://www.alema.com/mrs20-400-mini-guide-block-and-rail.html

 

[dave willmore]

Herring_fish,

Could your brilliant device run a CNC type of router or drill head?

If you've read the Sprung/Delbeek books, you may remember a proposal in the last one where a piece of glass in the tank periodically got a "windshield wiper" pass over it to scrub off algae and bacteria into the water to create waves of plankton.

With your talent you could have a wiper motor pass over a pane of glass or even rig a couple of motors and a rod between them to pass a dozen wiper blades over a series of plates.

Suppose you put a series of plates 1" apart and used a 1.25" or 1.5" soft nylon brush on a slow turning router or drill head to run between two plates at a time while spinning, then move an inch at the end and pass back between the next two panes? You'd have all the live planktonic bacteria and algae that your coral could eat, either in addition to rotifers or as a replacement.

I've never worked with CNC routers but it seems they would be a good fit in this two dimension application. It should be even easier to program an engraving machine or other natural two dimension mover to this application. You'd make the engraver or router move in a zigzag pattern -- right for 3 feet, over an inch, left for 3 feet, etc. until it spun through all the plates and went back to its home position to sit for 24 hours. If this were the part of the refugium with intense light and water flow, perhaps you could make two passes a day.

What do you think?

 

[dave willmore]

Here is a router slide made by Festool for around $130.

http://www.rockler.com/product.cfm?page=18942&filter=template large

One would have to mount a track on this slide and then use your type of mechanical brillance to run a slow turning router down the track to the end of the glass panes, then move the track an inch or so until it centered between the next two panes of glass.

For the router bit, I envision a nylon bottle brush that would need to be about 16" long for my particular refugium. I would guess these bristle brushes are made long enough that one could cut to a length to fit anyone's application.