DIY Diatom Filter for under $100.00

[Paul B]

Those old diatom bags are not easy to repair and I always felt they were a horrible design to begin with. But in the 60s thats all we had as the technology was not there yet.

Those diatom filters had a surface area of about two feed. The new design, the larger one I built has an area of I think 6' so it should be 3 times as efficient and much easier to clean. The filter cartridges can easily be replaced if need be but should last for many years with powder.

The entire unit is submersible.

I feel this design fixes the main problems of the old Diatoms. These won't rust, no seals to replace, starting is simple because that tiny bit of air left in the unit during starting goes right out. They don't over heat and won't electrocute you if they get wet.

They should be much cheaper than the original design in todays money. If a manufacturer decided to build there, they would go for the cheapest materials and you would have cheap garbage which is all that is out there now. Building these is simple but a few tools are required.

I designed a much simpler unit and if I get time will post it with materials. I want people to have these if they want without going broke because I have always felt that if it were not for Diatom Filters, I would not be in this hobby.

I also have always said that if my last diatom filter croaks, I will build a new one.

 

[MickeyCT]

Happy New Year!

 

[vahegan]

I am going to do that but it's not as simple as it sounds. The pleated "paper" on the end has to rest in a solid housing or the thing will just collapse with the suction of the water.

Now that I know the "Proof of Concept" and prototype works I designed a much simpler design that anyone can build quickly using the bracket that you can buy for these canisters. I will take these prototypes apart and build them using the new design.

Happy New Year!
Is there no plastic core tube along the filter length in the center? Something like a strainer they put in the end of the intake pipe of the freshwater canister filters? Otherwise, how are they supposed to work, only by pumping water into the inner area to prevent it from collapsing? That should also be relatively easy to fix if you drill holes, or better yet, cut longitudinal slots in a piece of PVC tubing, and then insert it into the pleated filter.

 

[vahegan]

Those diatom filters had a surface area of about two feed. The new design, the larger one I built has an area of I think 6' so it should be 3 times as efficient and much easier to clean. The filter cartridges can easily be replaced if need be but should last for many years with powder.

There is also the Nu-Clear canister filter by Inland Seas - their filter has the surface area of 30 sq. ft! However, their smallest cartridge has 25 micron pores, and besides, yes, they are pricey. Even though they are US-made and high quality workmanship, around 250 dollars for a pumpless device is a bit on the high side IMO.

 

[Paul B]

Is there no plastic core tube along the filter length in the center? Something like a strainer they put in the end of the intake pipe of the freshwater canister filters?

It's not just cutting the thing in half. Of course you can do that but the cartridge has a plastic cap on the ends that is molded into the filter material. That is needed so there is no by pass of the water. It has to be a tight fit. I can build it but first I will see if the manufacturer makes one.

I would have to remove one of the plastic ends and get all the filter material out of it. Not an easy job. Then the filter paper has to be form fitted into the end cap and the length has to be perfect because those canisters don't allow for any deviation in the size. Too small and the top won't close and to short and the water will by pass it.

 

[jjohnwm]

Paul, thank you for this entertaining and educational thread. I stumbled upon it while snooping around the internet, read it, and then immediately joined this forum based upon this single thread! I don't even have any marine tanks anymore, haven't had one for something like 25 years now; strictly a freshwater hobbyist now.

I was a Vortex Diatom filter user for decades, and have often toyed with the notion of building a modern-day version; yours is exactly what I envisioned. Now you've gone and done it; my build is gonna happen

Two questions for you. First, I have kind of lost track; where have you landed when it comes to porosity on the cartridge? Did 5 micron end up being too coarse?

Second is a bit more involved: how do you backflush your creation? I was thinking of connecting both the supply and return lines using valve-controlled unions; shut the valves, remove the entire filter using the unions and then back flushing with a hose at the slop sink. The canister would remain closed, but the whole gizmo would have to be removed and replaced each time. But I keep wondering if it would be practical to create some sort of Frankenstein arrangement of valves that would allow backflushing without removing anything, just attaching a hose that is used to carry the waste to the slop sink but use the filter's own pump to power the backflush.

Would a roughly-500gph pump be sufficiently powerful to dislodge and discharge the dirty powder? I'm on a well with a pressure-system, so I'm not sure that my whole-house pressure pump would even suffice.

I'm hoping to find that both the narrow and wide pleated paper cartridges are the exact same height, and than I can use or cobble a set-up using the narrow cartridge in the wider housing. I believe this would create enough space to allow for the easy installation of a vertical tube running to the bottom of the housing to keep the DE stirred up to facilitate coating the cartridge. Won't know until I go into town and have the chance to handle and examine the hardware a bit. Some info is tough to get off a computer screen.

Thanks again for this terrific thread! Cheers!

 

[Paul B]

First, I have kind of lost track; where have you landed when it comes to porosity on the cartridge? Did 5 micron end up being too coarse?

I use 5 microns on the larger one that I use diatom powder with just like the old Vortex. But with these models, you can't just put the powder in the canister like we used to do. There is no tube going down to the bottom so the powder will just sit there like a lump and not coat the membrane. You have to start the filter using a container in your tank so the top of the container is over the surface of the water. pour the powder into that container. After it runs clear and the powder is on the membrane, carefully remove the container by sinking it.

You just backflush that one to clean it just like the Vortex. No need to do anything crazy, it cleans perfectly and you end up with a new filter. Just connect the outflow hose to your sink or hose.

I probably have a picture on here someplace.

The smaller unit I built has a one micron element in it that is not pleated and you don't put powder in that one. You just run it like that. You can backflush it but almost nothing comes out so you need to run it in a container with some "Regular" bleach. No scents or no splash. It should be regular as those other bleaches are deadly poisonous. Personal experience.

I would not put a tube in like the old diatoms. I tried and there just isn't enough room even for 1/4" tube. It isn't needed and runs and starts very easy just as I said.

 

[fishybizzness]

Hi Paul! I'm in the process of building one of the filters you designed. I bought some 1 micron pleated filter cartridges as I plan on not using diatom powder. Do you think, because these filters are pleated, that they will be able to get clean by backflushing? Thanks for the help!

 

[Paul B]

I think you will be able to clean them for a while. Then the pores will be clogged to much and they won't work. But "regular" Clorox bleach should clean them pretty good. Make sure to only use "regular" bleach, it says that in the label.

 

[Axelrodi202]

@Paul B what cartridge size and pump GPH would you recommend for a 335 gallon tank? Freshwater planted tank, if that matters (perhaps more forgiving of stripping out all the fines from the water vs a reef).

Right now I have a spare 700 GPH Mag 7 pump I could use.

 

[Paul B]

The 700 you have should work fine. If you got a larger pump, you would have to make the entire thing larger because you couldn't push that much water through the canister.

 

[Axelrodi202]

I ended up setting one up tonight with a 20" cartridge and the 700 GPH pump. I noticed after around 1 cup of DE powder the flow started slowing down so I guess for that particular configuration, around 1 cup is the sweet spot (though I note you were using around a cup with the 10" cartridge)

 

[Naekuh]

i wonder, can you DE powder one of those marineland magnum internal filters which use those micron filters?

 

[SpyC]

I have 4 or 5 old Vortex Diatom filters in various stages of disintegration and I use one all the time to stir up the gravel in my 125 gallon tank. I also use it to blow out detritus in the pores my real rock. The tank uses dolomite gravel and the gravel has been in there for the 52 year life of the tank.



I also use the diatom filter many times when I collect NSW which is full of sea weed parts, sand and all sorts of debris because I take it from shore.



My last Diatom filter croaked after many fixes and modifications so I built one. I have been wanting to do this for many years because the manufactured model has not been built in many years and it was a horrible design for salt water and it rusted bad causing the bearings and seal to fail.

This working prototype I built in about an hour and so far it runs very well but I didn't put the diatom powder in yet.
The main two parts are a typical under sink water filter housing available from Amazon for about $20.00. The pleated filter cartridge inside is a 30 micron. They sell a one micron and if you use that you don't need diatom powder but I want to try this one first with the powder.

The pump is a 500GPH Supreme Hydro-Mag pump. $68.00 on Amazon

The membrane inside is $13.00​

Pentair Pentek R30 Sediment Water Filter, 10-Inch, Under Sink Pleated Polyester Filter Cartridge, 10" x 2.5", 30 Micron​

This is the finished prototype ready for testing.

The galvanized cap on the bottom of the filter is a 4" end cap for a dryer vent duct. It will corrode so I will replace it on the finished model with a rubber one available in a plumbing supply of Home Depot.

I also would not use that piece of "melamine" shelving material at the bottom as it doesn't do well with water. I will use either Plexiglass or varnished wood.

I also will replace that clear tube between the pump and filter with a 1/2" PVC pipe using a union in the middle for ease in taking the thing apart.

Unrelated tonfosh, that is a common scam. They will normally offer you something like their fake gold or fake high end clothing products in exchange for larger amounts of cash as a thank you. The person was dressed perfectly for the scam they were trying to run on you

 

[fishkat]

Evil1 The patent for the Vortex Diatom filter ran out decades ago. I have been using them since the 60s.

This model I am making is supposed to have the motor mounted on top of the filter housing. There are a few things to work out first but in either case, I want it to work very well and be easy to clean before I make the final model.

The problem with the pump on the top is that the slightest amount of air in it stops it. That was one big problem with the Vortex model. This is fun and I will perfect the thing. I just need a little time. Remember I put this together in less than an hour.

Steve, I do carry everything over to the sink. Only the hoses need to go in the sink, not the entire filter and the outside of the unit doesn't get wet.

Paul, I still have a working Vortex with the glass mason jar! How do you clean Your cartridge ?? The problem with having a sandbed is that some of the sand gets sucked in.
fishcat

 

[Katrina71]

I have never seen a diatom filter. Don't know how it works, but I'm intrigued. Does anyone have a video of how to use it?

 

[Paul B]

Unrelated tonfosh, that is a common scam. They will normally offer you something like their fake gold or fake high end clothing products in exchange for larger amounts of cash as a thank you. The person was dressed perfectly for the scam they were trying to run on you

I don't understand this at all.

I have never seen a diatom filter. Don't know how it works, but I'm intrigued. Does anyone have a video of how to use it?

You get diatom powder from a swimming pool supply, put a cup or two of the powder in it. Turn it on and watch the water disappear. I realize that is skipping over a few things but if you get one and need more info, I can show you.
When the filter clogs, you backflush it and the dirty powder goes down the sink.



Fishkat, just shake it and turn it over as you back flush it.

 

[Katrina71]

Ok, yours blows unlike the marineland that takes water in?

 

[SpyC]

I don't understand this at all.


You get diatom powder from a swimming pool supply, put a cup or two of the powder in it. Turn it on and watch the water disappear. I realize that is skipping over a few things but if you get one and need more info, I can show you.
When the filter clogs, you backflush it and the dirty powder goes down the sink.



Fishkat, just shake it and turn it over as you back flush it.

The scammers do it as a thank you. They'll normally say they don't have enough money for something and ask for help. As a thank you and a chance to get more money they offer goods that the common person may not be able to easily identify as fake on the spot as a thank you. You'll say something like 'that is a lot of gold and I only gave you $50, here is more money to make the trade fair'. I am unsure if you use reddit, but the scams subreddit has a lot more information and real world examples of this and other scams.

 

[ingchr1]

i wonder, can you DE powder one of those marineland magnum internal filters which use those micron filters?

Yes, but I'm not sure how much additional benefit one would see.