reverse flow sand bed filter

[mnewby]

I am wanting to incorprate in to my 125 gallon tank a snd bed about 2 to 3 inches of sand on a under gravel filter i build out of pvc pipe and egg crate what material can i use to keep the sand from going threw the egg crate yet still allow the water to flow up threw the sand bed i want to reverse flow the water from tank in to mairine land magnuim 350 canister filters and then under sand and threw bed can any one give me recomedations on a material that will hold find sand yet allow the water the flow threw it.

 

[azgard1]

Standard window screen material is your answer. Glue with standard pvc cement.

Reverse flow is very old approach and a Mag 350 will not create enough pressure for a proper reverse flow. I strongly recommend you consider some type of refuge circulation system.

All the best.

 

[Ricko]

I agree, very old approach. You could set it up as planned but without the flow through it.
Azgard1, your avatar, is it one of your fish? If so he looks fantastic!!

 

[mnewby]

i am running two of the 350 in to it im also using tha refugme in the sumpn tank

 

[lizardarm]

2"-3" of sand is going to be putting some back pressure on those Magnum canisters. I'd imagine that you'd end up with the water not dispersing but rather pushing through the sand in one spot. At best. Window screen is probably best, but it will eventually get clogged, then you're stuck with a non functioning, nitrate producing filter thing trapped below all of your sand and whatever else you put in there.

 

[Rod Buehler]

not only an old approach, but a poor one for a reef tank. you will only have aerobic bacteria in the sand bed and no anareobic. It will become a detritus trap and a time bomb that will need periodic cleaning to keep iyt from exploding, and/or frequent cleanings to avoid nitrate buildups

 

[mnewby]

i have a dimanod goby and a yellow watch in my 55 gallon setup now with the same cofig and they keep it under control the issue with door screen is it allows the sand to fall threw it need some thing finner

 

[nozleman]

+3 on forget that setup! You will eventually run into problems! Buddy did similiar approach, and was pulling hair out after one year!

 

[mnewby]

so far in the 55 gallon im having no issues with hair allerge just st that looks like small fine feather calipia the porblem is i need to find material thats will allow water to go threw but not the sand

 

[Ricko]

I think nozleman means his mate was "literally" pulling his own hair out, not the algae (big sorry if i am wrong).
The setup you want has great potential for aerobic filtration, but like everyone keeps saying it will cause problems in a reef tank. It will process ammonia and nitrite into nitrate too fast for any anaerobic bacteria to break down the nitrate, hence causing very high nitrate in your tank. I honestly would not employ this filtration, but if you are set on it, let us know how you go!!!

 

[kaskiles]

You could try something like this sintered ceramic shapes instead of sand:
http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=4169

At least that way you would not have to screen it off. But it will probably convert ammonia through to nitrate too quickly if you pump directly through it, I would think it would be safer to try to passively pass water around them so you get some of the denitrification activity they report in their pdf. Probably easier to clean this stuff too...

 

[mnewby]

i dont have a problem with the current system on nitrates because im also running a refugme i think people have the worng idea here im wanting to keep the snad on top of the egg crate what im looking for is idea of materilas that should allow water threw but keep the sand abouve it the ida with revurse flow is to keep as much stuff acumliating in the sand and keeping it in the water colom to be skimemmed off by protein skimmer

 

[kaskiles]

You could use nylon mesh fabric, if the window screen isn't small enough. That is what the magnavore simplicity media reactor uses, glued over a larger plastic mesh.

Only things I can think of to use a sand bed for are; dentrification, particulate removal, root substrate or critter home... You've said you're not worried about nitrates, and the Magnum would get ride of the particulates; so is this some sort of copepod or rooted plant home?

 

[balogh03]

i think people have the worng idea here im wanting to keep the snad on top of the egg crate what im looking for is idea of materilas that should allow water threw but keep the sand abouve it the ida with revurse flow is to keep as much stuff acumliating in the sand and keeping it in the water colom to be skimemmed off by protein skimmer

We all get what you are trying to do...and we are telling you that in most cercumstances it just won't work well. There just isn't enough pressure and flow to clean the entire sandbed with a return from a canister. Although, if you must do the "reverse flow", youcan buy window replacement nylon screening that is very cheap.

Thanks, and good luck

-augustus

 

[mnewby]

Only things I can think of to use a sand bed for are; dentrification, particulate removal, root substrate or critter home... You've said you're not worried about nitrates, and the Magnum would get ride of the particulates; so is this some sort of copepod or rooted plant home?


yes