Moving Bed & Algae Scrubber combo filter

[amwassil]

I have a 110 gallon stock tank with about 100 gallons of water for my three RES turtles. I originally had an Eheim Pro 3 - 2075 canister which worked well for several months and then started to leak around the hose connections in the filter head. I pulled the 2075 and put a Marineland C-220 and a Sicce Whale 120 on the tank while I figured out something permanent. That turned out to be a moving bed filter using 5 liters of Hel-x media in a 5 gallon pail. I later upgraded to a 10 gallon Brute plastic garbage can with 10 liters of Hel-x media. This filter is cycling fine and maintains the water very well. Except, a moving bed type filter is so efficient it creates an enormous amount of nitrates.

Of course, turtles don't breathe in the water, so a huge nitrate load is not detrimental to them as it would be to fish. However, my turtles didn't choose to spend their lives in a bucket of water in my apartment instead of a pond in the forest, so I want to provide them as pristine a habitat as I can. Hence, the search to find a way to eliminate the nitrates. I eventually discovered the algae scrubber!

So I am currently building a combination moving bed and algae scrubber filter in a 20 gallon Brute plastic garbage can. I have just completed the algae scrubber, using an
Expressions-LTD scrubber box and LED lights.



The first photo is the cradle to support the algae scrubber box. The green ring was cut from a plastic planter that fit exactly onto the inner lip of the Brute can. I could not just hang the scrubber on the Brute lip because it would prevent the Brute lid from closing. The white cradle was made from PVC trim board glued with PVC pipe glue. The green rim and PVC cradle support the scrubber box to just clear the Brute lid.

The second photo is the scrubber box, with LEDs mounted, in the cradle.

The third photo is the plumbing for the scrubber box. The pump is a Lifeguard QuietOne 1200 (317 gph). I put a PVC union inline to facilitate removing the spraybar/waterfall for cleaning. The mesh is nylon sewing 'canvas' purchased at Walmart. It's 12"x6".

The fourth photo is the plumbing in the scrubber box, and the scrubber box in the Brute.

The next step is to cut (1) a hole in the bottom of the Brute for a 1" bulkhead to mount the incoming water jet; (2) a hole in the side of the Brute for a 2" Uniseal to mount the PVC pipe for the gravity outflow.

[SantaMonica]

Have not seen a turtle build in several years. I hope it works great.

[amwassil]

I purchased a set of wood end tables today at Sally Anne for $10 each. They are exactly the right size to fit in the space where the filter will go. I have the current 10 gallon filter on an adjustable metal shelf, but it just supports the weight marginally. So I decided to use something stronger. The tables will sit one on top of the other and I will have to modify the top table by cutting the legs to get the correct height for the bottom of the new filter and cut a 2" diameter hole for the water jet to enter the bottom of the Brute can. The pump will sit on the lower table. I'll post photos when I've got the tables modded.

[amwassil]

Well, the Sally Anne tables were a little too big! So I googled a bit and found a nightstand at IKEA that fit exactly in the available space. It looks nice, too:

http://www.ikea.com/ca/en/catalog/products/90121234/

I cut a hole in the top for the water jet to enter the Brute and removed the bottom and back of the drawer so I can pull it out of the way for access. I also built a base to raise the nightstand up about 4 inches.

I had to finalize the stand under the Brute, so I could then determine the exact location in the side of the Brute for the return pipe.

[amwassil]

The first hole I cut in the Brute was the bottom hole for the input pipe. I mounted a 1" standard bulkhead with a rubber seal on the inside. I decided to apply silicone glue on the outside under the nut. So I then had to wait a day to give the glue a chance to cure before doing anything else. The next day I cut a 3" diameter hole in the side of the Brute to mount the 2" return pipe in a Uniseal. I also decided to apply silicone glue under the flange of the Uniseal on the outside. So again, I had wait another day for that to cure.

So, finally, yesterday I was ready to start final assembly. First step was to remove the 10 gallon moving bed filter and supports and swap in the 20 gallon filter and the Hemnes nightstand. Second step was to disconnect the plumbing from the old filter and attach it to the new one. All I had to do basically was cut some 1" tubing to appropriate lengths. After finding a few small leaks and three attempts later here's the new moving bed filter in action:



The black screen left of center is the top of the return pipe with a conical screen to prevent filter media from draining out of the filter. The spot in the center is upwelling water from the input jet at the bottom of the filter. Theoretically, the media sinks around the periphery and gets blown back up in the center flow of water. Interestingly, although this filter media has been cycling for about [three - correction: the oldest Hel-x has been in the water for nearly] 6 months already, it is still floating! It will only start to sink when the bacterial colonies on each piece of media reach critical mass. In the photo you can see media pieces of various colours. The darker the more bacteria is growing. The lightest pieces are those I added most recently, about two months ago.

So with the moving bed part of the filter working and free of leaks, next step was to mount the cradle for the algae scrubber:



Next step, mount the algae scrubber box and its plumbing on the cradle. I connected the LED panels and the pump and everything worked:



Here's the plumbing:



Looks like I'm going to add another ring of plastic around the inside:



[Added Jul11/15] One of the key features of a moving bed is enhanced oxygenation of the water. This is provided by injecting air into the input water flow. I neglected to post a photo of my air injection. I'm injecting air through two air hoses attached to the input pipe immediately above the cutoff valve with check valves (the small orange things in the photo).

[amwassil]

As of this morning, water parameters are thus:

pH: 6.2
NH3/4: 0.0
NO2: 0.0
NO3: ~80+
PO3/4: ~0.5+

I'll connect the algae scrubber to a timer today and run the lights 12/12 for the first week or two. The water pump is on 24/7.

[Devaji108]

cool setup! but dont you think the ATS would the trick with out the "moving bed" ( 1st i have heard of that)
any way cool setup!!

[amwassil]

Devaji108

Theoretically, you are correct. It very well might! However, right now the moving bed is cycling and the algae scrubber is looking cool and pretty. That purple light glowing through the side of the plastic can looks particularly beautiful. Once the algae scrubber is established and has eaten all the nitrates and phosphates, if water params look close to pristine, I will probably take out the Hel-x and see what happens over the course of a few weeks. Turtles dump a huge organic load every day, so filtration changes have to be done slowly so as not to lose the cycle. I will certainly report my results here as this develops.

[amwassil]

Here are my two girls:

and my boy, Alexander, using Augustina as a footrest:

Lights out in 5! Antonia peeking out to say goodnight:



Contentment means basking on top of a friend:

[SantaMonica]

I think turtles are in my future.