In the lab we have a Barnstead EasyPure RoDI water filtration system sold by Thermo Scientific (see experiment product list). The prefilter and UV lamp have expired and I bought the necessary parts to replace it. If you’ve lost your manual for the machine and don’t want to wait the two days to talk to Thermo Tech Support (electronically) then the part numbers for these pieces are: Prefilter (D50246) and UV Lamp (LMX13). I bought mine from VWR for quite a pretty penny (~$300 for both pieces).

Anyway the installation is pretty simple and straightforward, but I’ll walk you through it anyways.

Above is a picture of the back and side of the filtration system. The back panel contains the filter cartridges, and the UV lamp is accessed by removing the casing from the sides and back. In the above image you can see 3 screws on the side and 4 on the back around the rim. These need to be removed to get to the UV lamp. The black latch on the back needs to be pulled down to open the rear hatch.

Before you remove the screws make sure the machine is off and disconnect the power supply and the water feed lines. These are supposed to be a quick connect system but there was nothing quick about it for me. Eventually I gave up on removing one of them.

Once you get the top off, this is what you should see inside the device. The UV lamp is behind the water tank. Just follow the blue wires.

There it is. The lamp is enclosed in a metal cylinder. So gently pull on the black rubber cap to pull out the lamp. The cap protects the plug that attaches the wires to the lamp, so be gentle here. The lamp should come out quite easily, but the wires aren’t long enough to pull the lamp out all the way so you first have to remove the plug.

Slide the black cap back along the wires so you can see the plug and wiggle the plug until it detaches from the lamp.The plug does not remove easily, so be gentle but forceful. Once you get the plug off you can fully remove the lamp from the cylinder. Check out the difference between the new lamp and the old one below:

Yuck right! Now slide the new lamp into the cylinder about halfway and put the plug back on it. Again it is a snug fit so be gentle and strong. Also it is worth noting that according to the manual the slightest bit of perspiration and finger prints can ruin the lamp performance so wear lint free gloves.

If you get anything on the lamp (like I did because I didn’t read the instructions, you see kids this is what happens when you don’t follow the rules…) you can use isopropanol and a fiber free cloth (kim wipes work well) to clean the lamp.

Now let’s get at the prefilter. Since the top is off, the access is easier because the back panel isn’t latched onto anything. There are 3 cartridges in here all designed for easy removal. The one on the far right is the RO Prefilter.

According to the manual, this filter is designed for easy removal. WRONG! In principle you just slide the cartridge up and out, but the fittings are all really snug and taking this thing in and out isn’t an easy task. First pull it up so hard you are sure you are going to break something. Once it pops up you should be able to move it up to a keyhole type thing. From there pull it out so hard your arms come out from their sockets. If your shoulders give before the gasket you’ve done it right!

Then take your new prefilter and put it back in reverse order. Only instead of pulling this time you push. And you push so hard it feels like you are going to give birth. And I’m pretty sure I did!

When that is all in and snug you are done! Well sorta, you need to reset the RO prefilter timer. First put everything back the way you found it (reconnect hoses, plug in machine, put top on). Hold down the flush button and turn on the machine. When you see “reset RO” press Start/Stop and when you see “—” press it again. Then you are done with that.

Next you should see -d1 (or something like that) and press Start/Stop to start the machine and get it to do it’s filtering goodness. Now you are done!

Aside: I didn’t pay attention to which fitting the water feed in line connected to. There are three “ports” on the back of the machine. The top is water in, the middle is water out, and the bottom is an overflow line for the tank. I spent about an hour trying to put the water in line into the overflow port. Not fun. Below is a picture of a connection that is too small for a hose.

And below that is how it’s supposed to look, so don’t try and do what I did. (I ended up calling tech support and while they were little to no help, I managed to figure out the problem).

So I hope this helps you if you have a little trouble trying to figure out this machine, lost your manual, or something else. If it didn’t then I’m sorry you spent so much time reading something so useless to you, but hey that’s not my fault.

Now I can begin the Repeating Crumley Water experiment and get going on the E. coli growth experiments! Yay!