Shower Filter: Mats as Media

[MikeM]

A posting by MCA on the Atlanta club'c FB caught my interest:

"Shower Power

IMHO shower filters are one of the best nitrification filters you can create for a koi pond. Showers occupy a relatively small footprint, provide great conditions for aeration and gas exchange, and provide a wonderful home for nitrifying bacteria.

One of the main components of a shower are a series of stacked contains holding media. The containers typically have perforated floors to let water fall from one container to the next. The other main shower component is the media used. Showers have been made using every type of rock to be found including feather rock, pumice, and lava rock. Another type of shower media is made from various ceramic materials. Some of these materials can cost more than a semester at Georgia Tech.

Another choice of shower media is different types and shapes of plastics. These range from purpose designed media like K1 or bio-balls. to hair curlers. On specific type of plastic media I am trying in a shower is Matala matting. Matala matting comes in full sheets and half sheet (24"x39") sizes and in 4 densities.

I replaced the previous media I was using and have replaced it with two cartridges made from Matala grey super high density matting. This matting has more surface area per volume than Japanese matting and about the same surface area as the K1 media used in fluid beds such Nexus filters. Each cartridge is 4 solid sheets of matting separated by 3 layers of spacers. The spacers are made of strips of Matala matting.

It will take 6-8 weeks to see how well bacteria colonizes the matting. I can say that the initial aeration effect is very good. Each morning I get some white foam to remove that is created by dissolved organic compounds (DOC) having bubbles sticking together. This is much like the form created by a kid blowing air into a glass of milk via s straw.

Next time you build or remodel a koi pond, consider using a shower for nitrification."

Hey, Michael, let us know how this does for you.

[MCA]

I know nothing. But I know it very well.

Inspiration: Paul removed his BHM and replaced it with matting and bio-balls. https://www.youtube.com/watch?v=TVI5a9UYILQ



So far all I can judge is the aeration. I never got as much dry white foam in the morning with BHM or Cermedia as I do with the two matting cartridges. It will take a while to know how the nitrification is progressing. In the meantime my Aquadyne 4.4 can handle the load. Plus I cut the feeding significantly for a couple of weeks.

I think one of the keys to using matting cartridges is good mechanical stage filtering prior to the shower. Don't pump algae and fish poop onto any shower. Today the new sheets of PVC arrived for building a new water distribution box. The previous box had a floor with 1/4" holes on 1" centers. The floor of the new box will have 1/4" holes on 1/2" centers. that should make for a more even water spread and no pilling up of the water in the box. We shall see.

[yerrag]

Mike MCA,

Over time, how likely is it that these mats will sag? Let us know if and when it happens.

[MCA]

Don't know and no empirical data. Things that could impact sagging: weight of matting, weight of biofilm that will grow on matting, flow rate of water, width of gap between supports.......and maybe others.

[Akai-San]

Looks like a great set-up. Question: What does the top feed look like? How is the water equally dispursed to flow through the entire matala mat area? Any dead spots?

It was one issue that I came across when I first developed my first portable shower system using large circular planter pots (stacked above each other). I was able to get coverage and enough spacing between the media filled planters to get the water columns, but I'm not sure if ALL the media in the system is subject to constant water flow. I did encounter some dead areas as the water made its way through the planters. In a flat/rectangular cartridge system, do you use a number of pipe rows to get coverage? Please share pics for learning.

[yerrag]

Interesting use of the mats though. They can be washed and reused. And when it sags, sticking in a pvc pipe should help.

[ricshaw]

Inspiration: Paul removed his BHM and replaced it with matting and bio-balls. https://www.youtube.com/watch?v=TVI5a9UYILQ

Thanks for sharing Paul's YouTube video. I do not remember seeing it. I added it to my Favorites list.

[MCA]

Question: What does the top feed look like? How is the water equally dispursed to flow through the entire matala mat area? Any dead spots?

Water distribution box. I made one for the use with the previous media and it is in service right now. Today I got new sheets of plastic to make a new box. I will make and publish pictures when the box is ready. That may be a day or two.

And when it sags, sticking in a pvc pipe should help.

Exactly. The spaces I used were what was left over from cutting the matting to fit my trays. The matting is 24x39. I needed 24x33. So I removed 6" and then ripped that into three 2" wide strips. So with 4 layers of matting I had a total of 12 spacers. Four went into each of the 3 gaps between the solid sheets. No science to this. I just used what was available. It is all an experiment.

Thanks for sharing Paul's YouTube video. I do not remember seeing it. I added it to my Favorites list.

You are welcome. There was a series of videos from Paul about building that pond system. Definitely one nice system.

[MCA]

On another koi BBS I was asked the following:
Quote:

are you using matala only because its cheaper than bhm ? or do you generally feel its better

How do we define better regarding shower media? Seriously.

Better likely means the closest fit to a compromise between:

• availablity
• cost
• weight
• size
• frequency of cleaning needed
• ease of cleaning
• aeration performance
• nitrification performance (ammonia and nitrite at virtually zero)
• denitrification performance (nitrate at 50ppm or less)

In the States Matala is

• availability: readily available
• cost: relatively cheap (each cartridge was $130)
• weight: lighter weight than any ceramic or stone product for the same size especially when those products are wet)
• size each cartridge has the same SSA as 100 kg of K1 so very compact size
• frequency of cleaning: for all media that is a serious issue for the prior mechanical stage...ideally a drum or sieve
• ease of cleaning: very easy to hose and shake off a sheet of plastic matting
• aeration performance: Better than two trays of Cermedia and at least as good as 4 partial trays of BHM judging by the DOC foam in the morning
• nitrification performance: Too early to know, I have little doubt bacteria will from on sheets of matting
• denitrification performance: Likely there is where a ceramic or stone media has an advantage where pores nooks and crannies could have lower O2 areas.

My experience with years of using BHM was it does a good job. But you need a lot of it and in the States it costs as much as University tuition. Plus I don't want to pump water to the top of 4 trays if 2 or 3 trays will work just as well. Cermedia was a much better size and cost than BHM. But the 8 cubic feet I had was falling apart. I don't have access to feather rock or pumice stone. Lava rock is just something I do not want to try do to weight and possibility of clogging.

Bottom like....for now it is a return to cheap, dependable, and relatively inert plastic media.

[Akai-San]

I also have the same experience with the Cermedia. In an submersible system with normal flow-thru rates, I really like it. However, under any kind of falling water/shower condition, the Cermedia is quite brittle and wears very fast. It needs to be harder and more durable to be used in a shower application.

I just bought a whole case of J-Mat several months ago from Amazon.com - FREE SHIPPING to Honolulu! Woohoo...so price was right, and it is still my favorite media to use. Maybe I will try it out with my portable shower system. Test subject.