Deep sand bed in canister filter

[Frogmanx82]

After years of just fish only salt, I'm switching to soft corals in a 70 gallon tank. The tank isn't drilled so a sump will be tough. I would like to continue to use the Fluval 403 that has been flawless for 17 years.

The filter has 3 compartments. I am thinking of taking out two compartments and filling the bottom of the filter with 6 inches of aragonite sand, and then some lava rock and set the last compartment on top of the lava rock. In order to keep the height correct, I may have to modify the compartments rather than remove them, but the point would be to have no flow through the sand, flow around the lava rock and then go through some filter floss and a sponge in one compartment.

Any comments on this idea. It should do better than the standard setup of making nitrates that I have now shouldn't it?

 

[shaneh]

ummmm "Fluval 403 that has been flawless for 17 years"....thro it out! you should use an overflow box and make a sump or buy one so you can use a skimmer and put your heater and other items in the sump like carbon and phos remover.....you are very dated. look on here a bit you will learn alot and welcome to the site.

 

[Frogmanx82]

I kind of expected that response but it's not all that helpful. I'm not drilling the tank. I have 1 inch between the tank and the wall behind it so its not that I'm not educated in the technology, I'm limited in options.

Would a deep sand bed in a canister be useful or not? If I'm stuck with a canister, what's the best arrangement?

I could go with live rock instead of lava rock but i have some lava rock already so its easy enough to break up into smaller pieces. If I go with one working compartment, I could put phosphate remover in there along with a sponge. I'd only use carbon if I had an issue with contamination of some kind.

Has anyone played around with this?

I'm going to go with a Tunze nano 9002 skimmer which should fit well in the tank and appears to be highly rated though cheaply made. The visi jet has just not been a reliable foam producer and gives off to many bubble in the tank.

 

[luv4paws2]

I've read somewhere that lava rock can leech harmful things into sw. I ran an eheim canister for years with various chemical media. I really don't see how it could hurt to try the dsb, as long as no sand gets sucked into the motor. I'm pretty sure that for it to be effective you need to have good flow across the surface of the dsb to keep crud from settling there. Give it a try, if it doesn't work then it's not too hard to clean out the canister and try something else.

 

[mikejrice]

I think the flow through your canister filter is going to be too much and it will blow sand back into the tank. I also would not use lava rock as it will leech stuff into the water. I would use either live rock, dry base rock or bio media. While your at it you might as well keep a carbon bag in there too.

I also gutted a canister filter for my fresh water tank. Filled it up with bio balls and it seems to do much better. The mechanical filtration is not as good but it keeps ammonia nitrite and nitrates in check very well.

 

[noboddi]

I agree I think it would be too much flow. A HOB refugium with just sand should help. One of the big ones. A little bit of sand does a lot of filtering.

Alternative is to build a shelf and put the sand filter above the water line of the tank. Requires no drilling of the tank

 

[Frogmanx82]

Thanks for the input. After checking I see there is the opinion lava rock could be a problem. I might be able to get away with what I have because it was in a freshwater tank for several years but its a stupid risk to take. I'll just leave a sponge in that compartment or leave it empty.

I think you're wrong about the sand getting back to the tank. I'm going to drill some holes in the central compartment so the water flow will not penetrate into the sand bed, and really what do I care if a little bit of sand blows back into the tank. I bet more sand will get sucked into the filter than what gets through the floss and sponge.

I have no option for HOB, I'm an inch from the wall behind the tank.

 

[bergzy]

using a fluval or other canister filters will not achieve a deep sand bed. a well designed canister filter operates via fluidized flow...which in easy description means that the water flows down the sides of the canister filter and up (reverse) through filter media.

thus, you would be creating a fluidized sand filter. not bad for biofiltration but may create a detritus trap situation.

so, what have canister filters figured out decades ago that only recently reefers have discovered? yep, fluidized flow. it is in everything now: ca reactors, media reactors, biological sand filters...heck, even protein skimmers in a loose way.

for a softies tank...what do you 'really' need?

how would i set up a softie tank given the no sump specs.

what 'i' would do is this...

if you want a dsb...go ahead and put it in the display. 5 to 6 inches is the 'ideal'.

have good medium water movement...10x in tank turnover is good (but can easily be 5 or 6). hmmm...what comes to mind for this? ah! a tunze 6025 (modded on non modded). at about 600gph dispersed flow...it is awesome (a simple mod brings it to about 1100gph). the 6025 is modestly priced and works great...esp the redeisgned ones! right roger?

i will assume you have good lighting...so i will not dwell into that.

oh, back to the canister filter...

17 years eh?

hehehe...

i have you beat my friend...my fluval 403 has been going 20 years strong.

so, what is a canister filter good for?

nothing according to reefers.

for me?

i use it as an incredible chemical media reactor...read: not biological.

i stuff canister filters nicely with carbon, gfo and asparagus for chemical filtration...wait, skip the asparagus, i had that for dinner last night.

they have all the components required for excellent chemical media filtration. fluidized flow, generous media space and a built in pump...what else can you ask for?

another awesome feature of using canisters for chemical filtration? they are supremely easier to change media out. this was what they were designed for. i dont know how many frustrating moments i spent trying to screw and unscrew those blasted little nylon nuts on a phosban reactor. the new screw top phosban reactors...ehh, i wouldnt trust them to be 100% water tight for the life of the product. remember that it only takes one leak over a short period of time to create utter chaos. the leak ALWAYS occurs when you are on vacation btw!

so, what are good canister filters also known for? yep! unusually reliable water tightness. have i had one leak on me? sure. but the leak was very slow in my case and i easily caught it before causing disaster.

soooo...

back to your softie tank...

deep sand bed, about 50 to 100 punds of good live rock, gentle water water movement, temperature control and good lighting. do a 10% to 15% water change per month with rodi good salt mix and you should be a champ with your tank...with a little trial and error of course!

did i forget to mention skimmer? do you really need a skimmer? for a softie, even an lps tank...i found skimmers to not be an essential piece of equipment. my garage tank (clams, nems, softies and some lps) has been running skimmerless for two years with limited water changes and no skimmer. thrivie-ness of the tank? awesome. but i could be lying through my teeth now, couldnt i?

save some heart ache and headache...but save a lot of money because reefing is not that hard if you keep things simple. i found out the hard way!

 

[Nikee1404]

I don't understand how canister filters can't serve as biological filtration. You can put an array of media in to host beneficial bacteria like bioballs and biomax media. And don't some coral like ricordea prefer nutrient rich water? I'm curious is why I ask. I run my 20 gallon reef with a fluval 305.

 

[mfinn]

<a href=showthread.php?s=&postid=15456126#post15456126 target=_blank>Originally posted</a> by Nikee1404
I don't understand how canister filters can't serve as biological filtration. You can put an array of media in to host beneficial bacteria like bioballs and biomax media. And don't some coral like ricordea prefer nutrient rich water? I'm curious is why I ask. I run my 20 gallon reef with a fluval 305.

A tank with high nitrates isn't a nutrient rich tank.

 

[bergzy]

<a href=showthread.php?s=&postid=15456126#post15456126 target=_blank>Originally posted</a> by Nikee1404
I don't understand how canister filters can't serve as biological filtration. You can put an array of media in to host beneficial bacteria like bioballs and biomax media. And don't some coral like ricordea prefer nutrient rich water? I'm curious is why I ask. I run my 20 gallon reef with a fluval 305.

as i have observed those (in real life) who run canisters as biofilters tend to neglect maintenance on them...causing more than just high nitrates but a lot of doc's as well.

you 'could' run a canister as a biofilter but that is what your live rock in the display is for. i have run canisters (filled with bioballs, hair curlers etc) as biofilters on reefs (in time long long ago!!!) and was never happy with long term results. the amount of crud that collects on them is quite amazing even when i ran a prefilter sponge. in the long run, it was a lot more work to clean the media of accumulated detritus (without killing the bacteria) than it was worth. changing out chemical media is much easier as everything just goes into the trash.

but...you never know. there has been a lot of improvements since i started reefing in the early 90's. lighting, skimming, chemical media, ca reactors, kalk reactors, system controllers all contribute to easing husbandry. let us know in 5 or so years how your tank is doing in terms of inhabitant survival growth and coloration with canister filtration along with any other pieces of equipment/husbandry you are using.

 

[Frogmanx82]

Bergzy, I do not have upflow through the sand. I drilled holes in the center compartment and filled the bottom of the filter with sand, inside and outside the plastic compartments. There is no flow through the sand. The flow is bypassed through the holes I drilled.

It should work like a 5 inch deep sand bed. It took a full 10 pound bag of wet aragonite sand. 10 pounds might not be a whole lot, but its not negligible. I will probably use the center compartment for phosphate remover and then have some floss and a sponge that will be cleaned monthly in the top. I should not have to disturb the sand to clean the filter.

The canister used to fulfill the function of a biological fillter making nitrates. Now I hope it will convert some nitrates, have some chemical removal options, and filter out particulates. I am curious if others agree this is a better use of the equipment I have. I hope that with a skimmer and regular water changes with RO water I'll be in good shape considering my limitations.

Thanks for the replies.

 

[synofreak]

Looks like you cant do an HOB fuge, so heres my suggestion.

403 with GFO and Carbon only. Filter floss if you feel the need to polish. Stock sponges in, and let it run regular.

LR as main filtration in DT. "Remote" deep sand beds in the tank.
Big piles behind rock or in corners with minimal flow.

I run a 120g with HOB skimmer/HOB fuge/ Fluval 404 with stock sponges, carbon, and GFO.

NO nitrAte problems. While a DSB is great for No3 to gas, LR will accomplish the same thing, depending on the rock type and amount.

 

[Nikee1404]

Thanks for the info! I'll be looking to ditch my canister in the near future.

 

[bergzy]

<a href=showthread.php?s=&postid=15457535#post15457535 target=_blank>Originally posted</a> by Nikee1404
Thanks for the info! I'll be looking to ditch my canister in the near future.

hehehe,

it is pretty rare for people to listen to the experiences of someone who has been there and done that..only for them to repeat the cycle of hair pulling!

advice is a tough double edge sword. a lot of people ask me what i would do...not just about reefing but about a lot of things in life. when they dont hear what they want to hear they usually go ahead and do what they were going to do anyway OR they will keep asking and asking for the smallest inkling of possibility for confirmation. what happens with the latter? 'when' whatever goes wrong, then they blame ME for saying that i agreed with whatever. i cant count the times that this as happened...but i am foolishly optimistic that there are a few that can learn from my experiences and mistakes.

sounds like youre on the right track.