Fluval 404 / 405 DIY micron & sponge filter modification (Gunner's F404 Supercart)

[CWO4GUNNER]

This new thread deals with the actual assembly.

The first thing I knew I had to do was prepare the impeller cover for a mating surface that would somehow hook up to the giant micron filter and the little grates that are their to keep that from happening had to go. To I cut and ground them off with mt Dremel tool.

The most difficult part was finding a way to connect the giant micron cart directly to the impeller housing so that bypass would not occur the way it does in the stack basket assembly becasue of gaps and relief slots. A powerful glue was needed to attach the 3/4" male PVC fitting below. The PVC primer & glue made for a bond that even surprised me permanently bonding the fitting to the impeller cover as one piece. This OK because the impeller cover detaches and a spare can for use separately as part of the micron filter setup.

The corrugated hose and attached cart is an early peek, ignore for now.

Any questions on clarification so far please post them, otherwise Ill proceed on to the next step in a couple of hours.

 

[CWO4GUNNER]

No questions, I sort of anticipated this, go figure. But I keep my word and want to share this MOD so lets move forward to the next step.

Below you see the giant size “whole-house” micron polyester pleated filter which comes in microns of 1,5,10,30, and 50. The filter has a built in center support screen (not seen) to keep it from crushing in the center but no crush or tear protection on the sides so I cut and install $0.20 worth of plastic canvas and make an outer support screen cut to size, sewn and reinforced with glue for solid rigidity. Note the canvas is placed under the blue top and bottom gasket to insured outer load bearing should the canister lid require some compression on the filter will not get crushed, Also note trimming of the excess sponge glue so that future filter socks placed over the micron will lay properly without allowing water bypass.

If there are no questions Ill continue posting later today or tomorrow. So far my total investment is $0.35 for the PVC fitting, $13 for the micron filter, and $0.20 for the plastic canvas or $13.50.

 

[mott]

Good stuff!!! Curious to see if that pump will be functional with the new design. Is that a micron filter from a MAG?
Edit: I missed the part about the pleated filter.

 

[mott]

Hey, you will have extra room in the can now no? Any plans for filling the areas around the circumference filter if the pump can keep up?

 

[CWO4GUNNER]

Good stuff!!! Curious to see if that pump will be functional with the new design. Is that a micron filter from a MAG?
Edit: I missed the part about the pleated filter.

To answer your question I opened up the canister and simply unscrewed the cartridge for a photo comparison between the giant "whole house" & Magnum cartridges. The last photo is the built in internal plastic grid I was earlier referring to which is a separate item in the magnum.

The giant actually has a pleated surface area of more then 3X that of the Magnum cart becasue not only is it taller and bigger around but the folded pleats are 3X deeper to with 3/4 inch of center. I need to get the actual calculation on surface area becasue I forgot about the pleat size difference and that could mean that the giant has even more surface are then I first though, perhaps as mush as 10X that of the Magnum.

 

[CWO4GUNNER]

FYI, I calculated the flat surface area difference in size between the magnum & giant carts using the cylinder formula radius and height, pulse the difference in pleat size. The giant has a surface area 6 times greater then the magnum cart. What really blew my socks off is the actual pleated surface area of both which is almost unbelievable but the calculator and formula doesn't lie. Lets just say that it's at least 20X greater then a flat sided filters surface area.

So to say the least I expect great results.:grinyes:

 

[CWO4GUNNER]

Moving right along with an audience of crickets LOL, we get to that part that was difficult to work out but the end result was made easy for those interested (cricket-cricket).

Alrighty-then, since the intake port (now a 3/4" fitting) is offset and not inline with the cartridge, a 6" double ended threaded (gray) PVC pipe was cut in two and use for each end of the mating ritual (lol small pun). One threaded end 3" long to thread into a 1" piece of 3/4 ID corrugated tubing and the other end snugly slipped into the open end of the cartridge while plugging the other end with a custom cut 1/2" rubber plug (not viewed).

The male 3/4 inch white PVC fitting already PVC-glued to the impeller cover then simply threads into the other end of the 3/4" ID corrugated tubing. The small section of flexible non-collapsing tubing is essential in allowing the cartridge to both mate the union at an offset angle and maintain absolute water tight integrity preventing and eliminating bypass which is so prevalent in this model canister IMHO.

There are a few small boring yet critical details I left out but if your truly interested just PM me and I explain it. Otherwise if there are no other questions I will move on to the final phase of DIY assembly this evening.

 

[mott]

Very cool! Cricket! Is there any space around the pleated filter? Do you plan to put anything else around it if there is space?

 

[CWO4GUNNER]

Very cool! Cricket! Is there any space around the pleated filter? Do you plan to put anything else around it if there is space?

LOL, cricket means no one is interested so I write that, what you should write is echo-echo!
There is approximately 3/4 of an inch all the way round, not including the modified sponge insert compartment which we will get to in a moment, another bypass sieve that was in desperate need of major modification.

Anyway I digress, 3/4" all the way round the cartridge in the "basket section" which means that I have the option to add a custom made blue-bond sock and/or Poly batten sock both which will add bio (as if the massive sponge will not already do that) but more importantly further pre-filter what the course AC sponge does not catch adding life to the cartridge between bleach-water cleanings which means I will probubly have a very high endurance. If so I will eventually switch to a 1 or 5 micron giant cartridge and really get some serious polishing done.

See, this is why its great to ask questions and want to answer them even the hard ones that shed light on possible flaws and failures. Its call being objective and haveing nothing to do with personal fault, something we practiced at every meeting in the service for 30 years. Now of course we are all headed for change.

 

[Navyscuba]

Gunner You are the Master of DIY mods. hahaha Looking good.