jpmtotoro

up-side to this is using larger tubing and flushing it, like you say. downside is you'd likely be running the motors MUCH longer, which would wear them down much more quickly. try it and let us know

Ultimbow

i realy like your project because i am lazy too on that stuff but after spending that much money for a diy why not just go for aquamedic dosing pump same thing already put together and about same price.


http://www.marinedepot.com/ps_ViewIt...=&child=AQ4571

jpmtotoro

because to dose 6 liquids, it would have cost 720 bucks. instead, mine was about 500 i think. i wouldn't quite call that similar in price.

also, the programming is apparently a little odd, and the thing goes bonkers when there is a power outage and needs to be reset (or slap it on a battery backup). the crappy little lamp timers i used have small batteries in them so short power outages are already covered. so even if the price was exactly the same, mine works how i want it to, with a large degree of flexibility. priceless to me!

sometimes off-the-shelf stuff is worth it; but for some of the people here who have the capability to slap their own stuff together, it's good to see how it can be done. gives them a bit more freedom to set things up exactly how they'd like them to be.

why build a canopy? why build a reactor? why do any of these things on your own?


...because you can




on a side note, the first "problem" crept up. the self-adhering velcro strips i used... don't use them! the timers get luke-warm to the touch, which keeps the adhesive gummy. the timers started falling off the door recently (what has it been? 5 months or so?). so i hung corner brackets from the door and gravity shouldn't be a problem anymore.

lesson learned = no sticky velcro!

peanutbowl

just a little side note on the use of positive displacement pumps and neoprene hose. i work in a restaurant where these kinds of pumps are used for sauce portioning. managing a consistant portion is crucial to our product quality, therefore we have to calibrate these pumps daily. granted, our sauce pumps are much larger that the ones you are using for ferts, but i imagine you will run into the same kinds of issues. we use 3/4 inch tubing in our pumps. anyway, you will find that you will have to constantly increase the time that the pump runs in order to keep the same dose. for example, we have to change out the neoprene hose that comes in contact with the cam about every two to three months. if we don't, the hose bursts and we have a mess to clean up. when the hose is new, it only takes 2.5 seconds to move 10 oz of sauce. within a couple of weeks, that time will increase to anywhere from 3.5 to 4 seconds for 10 oz. by the time we change out the hose, i've had timers set up as high as 5.5 seconds for 10 oz. so keep an eye on your dose. and if you do ever change out your hose, be ready to cut back on time.
i do love the idea of not having to worry about dosing everyday. in my quest for automation in the tank, i'll definately keep this idea in my pocket. excellent read.

jpmtotoro

i will definitely have to keep this in mind. i'm HOPING that my application will out-last a commercial restaurant's sauce-delivery system. i'm running the pumps for 10 to 20 minutes per day usually, so i'm assuming the tubing will last longer. so far, so good. still tweaking fert quantities, trying to get them as "right" as possible; but that's no fault of the system. it puts in exactly how much i want, and when i want it; i just have to figure out what those magic numbers are!

apm

That is some crazy setup... I like it, how is it running after all that time?

Andy Ritter

After reading this thread, I thought that you might like to know about the experiment that I have started. I wasn't sure if I should start a new thread, but I finally decided to just reply to this one. My apologies if that decision was incorrect.

I too have been guilty of being too lazy to get up and go fertilize my tank. However, far more often the problem has actually been that I wasn't home to fertilize. For instance, a few weeks ago I went on vacation to Hawaii for two weeks. I was really concerned about the consequences of not fertilizing for that long, so I decided to have my in-laws to do it for me since they would be dropping by to feed the dog and check on the house anyway. However, I was also concerned about the in-laws not measuring correctly, so I had to measure out the ferts into individual containers with explicit instructions so the likelihood of messing up was minimized. I use PPS-pro, so that meant I had to come up with 28 containers for all of the pre-measured ferts. After going through that, I decided that enough was enough. I had read some of the other threads on APC about how others had tackled this problem, so I already had some ideas.

I also want to mention that laziness and absenteeism aren't the only reasons that I have wanted to automate the fertilization. I'm not a scientist, but logic tells me that most of the environments that our plants are from are probably relatively stable. I realize that rain storms occur and probably change the water parameters some, or maybe even in some cases, a lot. That being said, I doubt that in nature the plants have to deal with getting all of their nutrients for an entire day every morning before the sun comes up. They probably are more used to having the nutrients slowly leached into the water all day.

So for both of these reasons, I decided I wanted a system that would slowly drip the fertilizers in continuously. I wanted it to be accurate, dependable, well-made, and as fail safe as possible. I also didn't want it to be visible, since my aquarium is in the den of my house.

I looked at the enteral feeding pumps that are used to feed people through a tube directly into their stomach, but I decided that most of the ones available aren't designed for the extremely low rate that would be needed. They also aren't designed to pump against any back pressure, so I was concerned that they wouldn't be able to lift the fluid from down in the cabinet to up over the edge of the tank. On top of that, the ones that were capable of the low rates go for a lot on eBay ($200 or more, each).

Then I came across the infusion pumps that are used by hospitals to inject fluids into the bloodstream. These are capable of very low rates (as low as .1 mL per hour), are designed to pump against blood pressure (the one that I bought will raise the pressure up to 10 psi before sounding a warning that the tubing is clogged), have a built in battery to protect against power outages (mine will supposedly run for 4 hours on the battery if dosing 125 mL per hour, and even longer if dosing at lower rates), are computer controlled and programmable, and on top of all that, they are made to be used on people, so they are very well made.

After researching the best that I could, which involved intensive internet searches, talking with a cousin of mine that is a nurse, and also calling facilities that service these pieces of equipment and asking to talk to the service technicians that know the most about them, I decided that getting one of these would be worth trying. Then I just had to figure out which one to buy. That decision came down to mostly economics. Keep in mind that most of these pumps are several thousand dollars when new (I found out that hospitals don't even buy them; they lease them). However, there apparently is a pretty big market for older models that have been taken out of service, especially on eBay. To make a long story short, I chose the IMED Gemini PC-2TX pump, which is actually two pumps in one. With this one unit, I can independently pump two separate fluids, which made it perfect for PPS-pro usage. Here's a link to a site that has some information about the one that I bought:

http://www.firstbiomed.com/catalog_m...uip_therapy_id

I managed to get an exceptional deal on eBay (I paid less than $52 total), but even so, there are plenty out there for less than $100 including shipping. Then the only thing you would have to do is get the specialized (and required) tubing sets that go with the specific pump that you buy. That, I have found, is considerably more difficult to do than buying the pump. However, the infusion sets do appear on eBay occasionally, but as I said, they are specific to the particular pump that you buy. Fortunately, I was finally able to get a supplier convinced that I wasn't going to use these on people and was able to buy four sets for about $45 (everyone else had said that I would have to have a license to buy them). Therefore, I have invested right at $100 for my system, and in theory, should only have to replace the tubing sets every so often (that's why I bought four; I have a spare pair when the first pair splits).

I decided to mix up my PPS-pro solutions at one-half strength, so I just used two liters of water instead of one liter. The only difference is now I dose twice as much. I have a 75 gallon tank, so I set both pumps to infuse at .6 mL per hour. It's been going for almost a week now, and so far I haven't experienced any problems. I have no idea how long the tubing sets will last before they develop splits, but I'm hoping that they will last a really long time.

Right now I have the hoses on the suction side just sticking down into the bottles of solution. However, I am planning on getting some graduated containers to put the solutions in so I can compare the actual amount left in the containers to the amount that the pumps say they have infused (I did some test with the pumps before I actually started using them on the aquarium to check the accuracy, and even though it wasn't exactly the same, it was within a mL after 24 hours, and I can always change the programming if necessary).

I hope this information has been helpful. I would be happy to provide pictures and more information if requested.

Andy

Andy Ritter

The following is in response to a PM that I thought others might like to read:


Hello,

Thanks for letting me know that you liked my post. You are the first one to take an interest. I figured when I posted what I was doing with this pump that lots of people would be excited, but that hasn't been the case. Maybe there aren't as many people interested in automation as I thought.

I'm still in the experimentation phase of this project, so it's a good possibility that things might change, but I'm happy with how it's going so far.

I'm going to have to break my response up into pieces, since after typing it up and trying to submit it, I received a warning that the text was too long, so here's part 1:

I had two thought processes that led me to the conclusion that I should try mixing at half strength. I had always fertilized using fertilizers sold for aquariums, most recently with the Flourish line from Seachem. I was having a very difficult time achieving the "recommended" amounts of NO3, PO4, and Fe using these products. I started buying the dry ferts and experimented with adding them in order to achieve the proper amounts in the water. The plants started doing much better, but I found myself testing the water a lot in order to fine tune the amounts of the ferts to add. This became a pain, so I researched other methods. I decided that the PPS pro method sounded like the best option, since I like to enjoy my tank, not constantly work on it (don't get me wrong, I enjoy trimming the plants and doing the occasional water change, but only about every 2 to 3 weeks). When I mixed up my first batch of PPS pro, I noticed pretty quickly that the macro solution would get a precipitate that would settle to the bottom, and I would have to shake it up every time that I fertilized. When I got this pump, I figured that if there was more water, there would be less of a chance that a precipitate would form. I went with twice as much water since that makes the calculation for dosing really simple. I am no longer having the problem with the precipitate forming (which answers your second question). Another reason that I thought this would be a good idea was for better fine tuning of the fertilization. The infusion pump is capable of flow rates as low as .1 mL per hour. However, I wasn't sure exactly how accurate it would be. Granted, it is a medical device, so the technology, fail safes, and accuracies have to be very good, especially considering how quick people are to seek legal action in today's society. None-the-less, I figured that it might be more accurate at slightly higher flow rates (I don't have any info that proves that, it just made sense to me for some reason). Since my tank is 75 gallons, according to the PPS pro system, I should dose 7.5 mL per day (only a little more than .3 mL per hour). Since I mixed my solutions with twice as much water, I have been dosing at .6 mL per hour (which is 14.4 mL per day, instead of the instructed 15 mL, but I decided to go with the slightly lower amount for now). With the solutions mixed at half strength, it will be much easier to tweak the amounts added to the tank (although I have been so busy over the last few weeks that I haven't really had a chance to get into that too much).

Andy Ritter

Part 2:

I started using the PPS pro system in March, and quite honestly, have been so busy since then, that I haven't been testing the water parameters to see if I needed to tweak how much I have been adding (I guess I just trusted the system so much that I felt like I could get away with not testing as much as I had been). I installed the infusion pump on August 1st with the initial setting of .6 mL per hour, using the new batch of PPS pro mixed at half strength. On August 16th I tested the water for the first time since March, and was shocked at my findings. The Fe was at .1 ppm, PO4 at .65 ppm, and the NO3 was at 50 ppm(the test kit only goes to 50, so for all I know it might be higher than that)! This actually doesn't have anything to do with the infusion pump itself, but more to do with PPS pro, since I'm basically dosing the same, if not a little less, than I was before by just measuring and pouring. Since the Fe and PO4 are within acceptable limits, I don't think that I will adjust the dosing amount yet. I have been having a pretty bad issue with BBA, but it has been dying off for several months now. When it dies it lets go of whatever it is attached to and then gets sucked into the filters. I haven't cleaned the filters since June (and when I did they had huge amounts of decomposing BBA in them), so I'm hoping that the elevated levels of NO3 are just from dirty filters. Once I clean them and do a water change I'll start checking the water parameters more often so I can see if the dosing amounts need to be changed.

Your last question will be more difficult for me to answer. I haven't been able to find specifications that say exactly how much head height this pump is capable of. However, when trying to decide between an enteral feeding pump and an infusion pump, I just used my own logic to decide that an infusion pump would be better (which very well might be all wrong). For instance, I saw this thread for automatically dosing a reef tank: http://www.aquaticplantcentral.com/f...eeder-diy.html . It got me really excited about trying something like this, but the more I looked into enteral feeding pumps, the less that I thought that they would work. For instance, most of them are only able to go down to 1 mL per hour. The EnteraLite Infinity pumps that SantaMonica used for his reef tank are able to go down to .1 mL per hour, but they are expensive. In fact, I watched some on eBay for weeks hoping to get a good deal, only to see that they always go for way more than I was willing to spend. I just checked completed listings for the last 30 days, and the cheapest one sold for $248.50, with one going up to $350.00! Since I needed two of this style pump, I abandoned it as an option. On top of that, even if it was cheaper, the instruction manual for that pump states that it maintains a +/- 5% accuracy, but only if the head height is +/- 12" from the center of the rotor. I was concerned that this would be a problem, since my pump is sitting in the bottom of my cabinet, and the tubing rises about 53" before the fluid drips out into the water.

Andy Ritter

Part 3:

SantaMonica had his pumps sitting on top of the tank. One thing going for him was that an enteral feeding pump is designed to pump thicker liquids, and since he is using it to feed corals, that was an advantage. I don't know a whole lot about what types of liquids an infusion pump would be normally used for, so I don't know if they are capable of pumping thick liquids or not (the instruction manual for my pump states that it can infuse "intravascular drugs, fluids, whole blood, and packed red blood cells"). My thought process was that an enteral feeding pump is just pumping a fluid into your stomach, but your stomach isn't trying to pump anything back out (my theory might be flawed, so those in the medical field, please don't yell at me). I figured that since an infusion pump is for pumping liquids into your blood stream, and that your heart is developing pressure too, that an infusion pump would be better since it is designed to work against that pressure. I don't know if the thick liquid/no pressure property is comparable to the thin liquid/backpressure one or not, but my theory was that an infusion pump would be best. In the three weeks that I have had it set up, I haven't had any problems at all. The pump has the ability to check for air in the hoses and for an occlusion (blockage), but it hasn't alarmed yet, and at this point, I doubt that it would. Every time that I have looked at the ends of the hoses where the fluid drips out, there is always a drop sitting there waiting to get big enough to fall, and I've watched them drip in (although I haven't timed how long it takes between drops, but it's quite awhile). I was somewhat concerned that I might end up with a crust forming at the ends of the hoses, but that hasn't been an issue (I don't have the hoses below the surface of the tank water because I don't want to siphon out the tank water in the event of a hose failure). Besides, I think that the pump would be able to develop enough pressure to push it off anyway.

I hope that this information has helped you. I have communicated with the company that I bought my infusion pump from, and they said that they have many more of them. It is possible that they might be able to work out a deal for others from APC, but I can't promise that. Even so, there is another eBay seller that has 50 available using Buy It Now for about $85 including shipping. There is also someone with a couple of cases of the infusion sets that we could possibly buy and then distribute to each other. I am still using the first pair of tubing sets, and my plan is to continue to use them until they develop a leak, just so I can see how often they should be replaced.

It took me several hours to compose this reply, so I’m going to post it in the thread as well in case others might benefit from the information. I’m subscribed to the thread with instant email notification, so I’ll see if you post any more questions on the original thread. That way we might can get more discussion going.

Andy