DIY Fluidized Sand Bed Filter?

kavin2845

Gambusia
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Jun 26, 2012
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Malden,Massachusetts
Has anyone on here made one of these? i really wanna try one out for my 75g, any good threads or videos online?

Thanks!
 

duanes

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I made this one from plans on FAMA magazine, issue was from sometime in the 90s, if I find it I'll post the date.
Originally it had a closed top, but I found the closed/under pressure type was not needed.
Even with a check valve, during a power outage the sand has a tendency to back siphon, and I found it easier to do maintenance on without a cover.


The one in my pic is about 4 ft tall, and 8" in diameter, beside biological filtration, aragonite sand was used to help buffer alkalinity.
I've seen DIY versions made from 2 liter plastic coke bottles.
 

kavin2845

Gambusia
MFK Member
Jun 26, 2012
985
0
16
Malden,Massachusetts
I made this one from plans on FAMA magazine, issue was from sometime in the 90s, if I find it I'll post the date.
Originally it had a closed top, but I found the closed/under pressure type was not needed.
Even with a check valve, during a power outage the sand has a tendency to back siphon, and I found it easier to do maintenance on without a cover.


The one in my pic is about 4 ft tall, and 8" in diameter, beside biological filtration, aragonite sand was used to help buffer alkalinity.
I've seen DIY versions made from 2 liter plastic coke bottles.
wow thats big! did you notice a big change in water parameters when cycled? was the water cleaner? do you have any detailed designs? also is the diy ones mad from a 2 liter plastic coke bottle be enough for a 75g?
 

duanes

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These filters are not mechanical, and do not clean the water in a visual sense. They are biological, the sand is a substrate for beneficial bacteria, and the movement (fluidation) of media, in theory, sloughs off older non vibrant bacteria leaving room for more robust individuals. In essence a fluidized bed replaces bio balls or other such stuff.
I actually thought of mine, as a fluidized reactor as opposed to a filter.
I noticed when testing, that my alkalinity didn't fall as far between water changes, and when it did start to fall, I would know to add more aragonite to replace the sand that had dissolved from the acid produced by the fishes constant urination.
I used an average of 5 LBs of aragonite as media, and ran the influent line at a rate of 500 gph to get enough movement for the weight and mass.
 

kavin2845

Gambusia
MFK Member
Jun 26, 2012
985
0
16
Malden,Massachusetts
These filters are not mechanical, and do not clean the water in a visual sense. They are biological, the sand is a substrate for beneficial bacteria, and the movement (fluidation) of media, in theory, sloughs off older non vibrant bacteria leaving room for more robust individuals. In essence a fluidized bed replaces bio balls or other such stuff.
I actually thought of mine, as a fluidized reactor as opposed to a filter.
I noticed when testing, that my alkalinity didn't fall as far between water changes, and when it did start to fall, I would know to add more aragonite to replace the sand that had dissolved from the acid produced by the fishes constant urination.
I used an average of 5 LBs of aragonite as media, and ran the influent line at a rate of 500 gph to get enough movement for the weight and mass.
So how do you prefilter before water enters?
 

duanes

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I use filter socks (bags) in sumps as mechanical filtration. Because I have multiple tanks on a single sump I find socks to be most efficient, and the easiest to clean, rinsing them our about once per week. And I don't prefilter before the FB, there is just a line from simp to FB, one of the filter socks in the pic below is after (hanging on the efluent) of the FB

In a more conventional sump below
 

kavin2845

Gambusia
MFK Member
Jun 26, 2012
985
0
16
Malden,Massachusetts
I use filter socks (bags) in sumps as mechanical filtration. Because I have multiple tanks on a single sump I find socks to be most efficient, and the easiest to clean, rinsing them our about once per week. And I don't prefilter before the FB, there is just a line from simp to FB, one of the filter socks in the pic below is after (hanging on the efluent) of the FB

In a more conventional sump below
Ive never used filter socks before, i was wondering if you had like a back up plan like if the sock gets clogged and overflows, how would you stop that?
 

kavin2845

Gambusia
MFK Member
Jun 26, 2012
985
0
16
Malden,Massachusetts
I made this one from plans on FAMA magazine, issue was from sometime in the 90s, if I find it I'll post the date.
Originally it had a closed top, but I found the closed/under pressure type was not needed.
Even with a check valve, during a power outage the sand has a tendency to back siphon, and I found it easier to do maintenance on without a cover.


The one in my pic is about 4 ft tall, and 8" in diameter, beside biological filtration, aragonite sand was used to help buffer alkalinity.
I've seen DIY versions made from 2 liter plastic coke bottles.

What type of sand do you use? play sand, PFS?
 

duanes

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Jun 7, 2007
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Isla Taboga Panama via Milwaukee
If the sock overflows, it overflows into my sump,(same as when a hang on the back when clogged flows into a tank) and is no big deal.
But if they are rinsed regularly this doesn't happen. I usually have 2 socks for each outflow pipe (one on the pipe, and one already cleaned), and switch them out .
Some people put them in a washing machine without soap, some soak the sock in bleach overnight.
I have found the bleaching does a great job, you just need to rinse and soak the sock again in water with a dechlorinator.
I use aragonite sand, it is fine crushed coral, normally used as substrate in marine tanks.
It tends to turn the water a bit milky when new and first put in.
 

kavin2845

Gambusia
MFK Member
Jun 26, 2012
985
0
16
Malden,Massachusetts
If the sock overflows, it overflows into my sump,(same as when a hang on the back when clogged flows into a tank) and is no big deal.
But if they are rinsed regularly this doesn't happen. I usually have 2 socks for each outflow pipe (one on the pipe, and one already cleaned), and switch them out .
Some people put them in a washing machine without soap, some soak the sock in bleach overnight.
I have found the bleaching does a great job, you just need to rinse and soak the sock again in water with a dechlorinator.
I use aragonite sand, it is fine crushed coral, normally used as substrate in marine tanks.
It tends to turn the water a bit milky when new and first put in.
do you think regular playsand or PFS would work also? since i dont want to increase the PH in my tank?
 
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