DIY "Drews Doser" Peristaltic Dosing pump

[der_wille_zur_macht]

Telly, thanks for the info. That's about what I figured. I have plenty of room and want something that'll last 10 years, so these "cheap" pumps are likely not realistic.

The cost comparison is absurd

Watch eBay for a while! You could probably assemble a dual-head pump for about the same cost as this DIY project.

 

[TellyFish]

Watch eBay for a while! You could probably assemble a dual-head pump for about the same cost as this DIY project.

Hey der_wille- You must not have read the end of my post, I have bought almost all my masterflex part off eBay. I picked up my 77300 pump for dirt-cheap. Only government agencies or private research companies can afford to buy this stuff retail!

That's why we need to build these DIY!

 

[SWINGRRRR]

Hey der_wille- You must not have read the end of my post, I have bought almost all my masterflex part off eBay. I picked up my 77300 pump for dirt-cheap. Only government agencies or private research companies can afford to buy this stuff retail!

That's why we need to build these DIY!

X2. All 3 of my Masterflex pumps come from Ebay. I maybe have $200 total in all 3.
They say if you use a Masterflex for 20 years, you still have 30 years of service left in it.

 

[golfish]

I have one of the older Liter Meters. I bought it used around 1999 or 2000. Its amazing how long this pump has held up. I'd think Spectrapure has more money tied up in the metering end of these units. The pinch rollers and motor seem really cheap but its held up really well.

We use the Masterflex units at work in the Coke lab. Great stuff, over built and bigger then some tanks I've seen.

Great stuff there Killab443....

 

[Hawkdl2]

What Mark said. I don't have a litermeter, but it and DD's are hobby grade pumps whereas Masterflex/Cole-Parmer are laboratory/industrial grade units, but then reef keeping is only a hobby. I've used dozens of various Cole-Parmer/Masterflex pumps in the lab and there is no comparison is terms of reliability and build quality, but while I would, and do, use nothing else for things like remote water changes, they are not appropriate for most of us in in-stand applications - they're just to bulky. Conversely, I also have various chromatography systems that use much smaller pumps like the ones Killa found. They do fail on occasion, but I've also seen a number of the CP/Masterfelx pumps wear out - it happens. Nothing lasts forever.

Killa, that's a great site and I'm ordering out a couple for dosing applications, though I will probably buy the slightly more expensive but heavy duty versions on their site. Good find!

If you can find them in the US, Wellco makes nice smaller encased peristaltic pumps too.

 

[FiReC]

$4.75 for a set of replacement hoses from APT too, I like that! Might have to try one of these! How do you like it so far killab443? consistent?

 

[ErikJL]

Has anyone thought about using a large syringe, a low-geared liner actuator, and a pair of check valves? Linear actuator pulls syringe back, pulling in liquid via input valve while output valve stays shut. Linear actuator then reverses, valves are reversed so the liquid goes into the exit valve into the sump.

 

[BeanAnimal]

DIY "Drews Doser" Peristaltic Dosing pump

As many of you know, Bulk reef supply hasn't really been able to keep stock on these excellent pumps. Not only that but at almost 90 a pop they aren't too appealing for everyone's wallets.

Well they certainly are selling a lot at $90 if they can't keep them in stock

 

[BeanAnimal]

Anyone have info on how these stack up in terms of reliability or sturdiness to conventional peristaltic pumps? i.e. a Masterflex?

Note the same class of pump

The masterflex pumps are built to a much higher tolernace. In many ways they are easier on tubing, but at the same time because the pinching force is higher, they are also harder on tubing. That is you get more precision, but at the cost of tubing life.

 

[BeanAnimal]

Has anyone thought about using a large syringe, a low-geared liner actuator, and a pair of check valves? Linear actuator pulls syringe back, pulling in liquid via input valve while output valve stays shut. Linear actuator then reverses, valves are reversed so the liquid goes into the exit valve into the sump.

Yup... a few people have even posted working examples... Others have purchase surplus syringe pumps from eBay. I wne t as far as to design my own pump fixed displacment pump with integrated check balls... will likely never have it built though, as peristaltic pumps are just so easy to deal with.

 

[killab443]

$4.75 for a set of replacement hoses from APT too, I like that! Might have to try one of these! How do you like it so far killab443? consistent?

Works excellent. Very consistant. I accidently let my alk one on for about 8 hrs last week. I was messing with plugs on my aqua controller and put it in the wrong outlet. Nice cloudy mess I came home to. I lost a hulk monti and dispar antheas .

Has anyone thought about using a large syringe, a low-geared liner actuator, and a pair of check valves? Linear actuator pulls syringe back, pulling in liquid via input valve while output valve stays shut. Linear actuator then reverses, valves are reversed so the liquid goes into the exit valve into the sump.

IMO thats a Rube Goldberg and chances of something failing in a system like that are high. If it fails often and dosn't dose, it's purpose of convience is no longer there.

ALSO There's actually a video of one of these syringe style dosers on youtube somewhere.

 

[BeanAnimal]

IMO thats a Rube Goldberg and chances of something failing in a system like that are high.

Syringe pumps are used every day in the medical and scientific world. There is nothing Rube Goldberg about it. Reliability is a function of design, a syringe dosing setup can easily be as reliable as a peristaltic setup. Both are postitive displacment pumps that have wear parts and need maintenance.

http://www.syringepump.com/special.htm

http://cgi.ebay.com/LOT-TECAN-CAVRO...emQQptZLH_DefaultDomain_0?hash=item414cc01560

They come in all shapes, sizes and configurations... both for single stroke infusion and continuous dosing. Some use off the shelf plastic syringes, others use proprietary industrial metal syringes. Nothing Rube about it.

 

[killab443]

What I thought he was refering to was the DIY syringe pump. Found that video on youtube. http://www.youtube.com/watch?v=TmWOykWHEKA.
IMO I do not think this is reliable. This is exactly what he is considering in a DIY project.

Those medical grade pumps are great your, your right definitly nothing Rube Goldberg about them.

 

[BeanAnimal]

With a little effort one can construct a reliable syringe doser... However, the peristaltic doser is certainly much easier for the average person to build.

I would certainly hope that the YT video project ended up beign further refined than a block of wood on a 1 RPM motor

I ended up building a Atmega128 based controller for the peristaltic (Masterflex) pumps for dosing and (eventually) automated water changes.

Glad you enjoyed your project

 

[Hawkdl2]

2 Master Flex pumps and a few solenoids automating Kalk, ATO, and water exchanges. I'm using an Apex controller. An additional small peristaltic pump drains away OSW from the sump at the DT during exchanges.

We use piston pumps and syringe dosers in my lab for various specific applications (like filing vials with experimental biologics for clinical trials) where very accurate small volumes are required, but I don't see them being appropriate for most reef applications. We use peristaltic pumps for every application that I would consider similar to those we see in reefing.

 

[BeanAnimal]

I would imagine a better use for the sryinge dosers would be for zeovit or similar systems were multiple products are used in small amounts on a regular basis.

My design for a positive displacment piston pump was for doing continuous water changes. I did not want to have to worry about keeping two peristaltic pumps sequenced with regard to flow and/or worry about tubing failure. In the end I have no desire to have the parts built and don't have the tooling to do it myself.

 

[Hawkdl2]

To avoid sequencing the pumps, I perform small volume a sequential addition/subtraction of about a gallon or so at a time - as frequently as I desire. Float switches, with emergency back up switches keep the pumped volumes correct and over ~6 months now, my tank's SG has remained perfectly stable. It works well and easy to set up. Tubing failures can occur, but are rare with Pharmed tubing and Masterflex pumps if replaced regularly. Recognizing "anything" can happen, I also have time limits on the two pump functions. Worse thing that can happen is a gallon of water hits my garage floor before the system shuts off the pump.

 

[ErikJL]

You guys are correct, but here's one that more accurately shows what I had in mind:

http://www.youtube.com/watch?v=8uIymKcx-qg&NR=1

Will it be less robust? Probably, just as any DIY project is likely to be less robust than a manufactured item. But if you like to tinker, as I do, these things are just cool.

 

[CorkPullerPHL]

What model's of Masterflex are suitable to reefing? A quick search yielded a ridiculous number of results.

 

[FiReC]

ordered my parts for the drews doser from apt today, can't wait!

I don't know if anybody noticed, but you can get it fully enclosed with a power cord for 97+shipping from apt as well in case you didn't want to enclose it yourself.