DIY Sump (Wet/Dry) Basics

[drdud]

I would like to change my filtration from HOB (AquaClear 110) on my 55-gal mbuna tank to a sump. I like my Aquaclear sponge media (cheap, reusable) and use the ceramic beads as my biofilter. My tank is overstocked, so I really need more filtration. (I would love to solve my overstock issue with more/bigger tanks, but . . . . . perhaps another time.) I could add a second AquaClear 110. However, as much as I like the HOB, I would like to increase the flexibilty of media options (such as floss for a fine filtration) and increase the water volume. I have seen some DIY projects that use the plastic drawers and Rubbermaid containers with a pump to create wet/dry set and wonder if this would be a way to increase the effective water volume of my set-up without increasing the tank size.

Just so everyone knows what style I am talking about, I have a basic sketch.

Questions:
1) Is there a rule of thumb for what the desired flowrate of the pump should be? Is this based on a desired number of water volume turnovers in the tank over time?

2) Can I keep most of the drawers under the water line and rely on the fact that as the pump returns water to the tank, it will cause the water in the drawers to fill the main reservoir, or will a system like this only work with the water trinkling through the drawers? (A little concerned with 'drippy noises')

3) How much bio filtration media is really needed? I have seen in other threads they talk about "gallons" of volume. However, I only use a few pints of ceramic beads and it seems to be fine. Is there a rule of thumb?

4) I am thinking about Drawer #1 using a sponge media (probably the AquaClear sponge or equivilent. Drawer #2 would be bio media (probably the ceramic beads). Drawer #3 could be used for charcoal or other chemical media if need. Sound like the correct arrangement?

5) Has anyone ever used a plastic screen laid over plastic grid ('light diffuser" material we use on the bottom of the tank to distribute the weight of rocks) to make a housing for polyester floss material? I have a vision of this resting over the top of my bio filter in Drawer #2. This would be after the 'course' sponge, so it would not clog as quickly.

6) I assume the tubing/piping sizes are a function of the discharge of the pump. I figure once I know the size of the pump, I can figure out the size of tubing/piping and the number of spray bars, etc.

I understand that this discussion does not include the overflow box. I can save that for a later thread, if needed. I searched for other discussions and have read a lot of information. Sorry if this is a repeated question.

 

[RodInCALIFORNIA]

the size of the return pump is ruled by the max flow of your overflow box. say your overflow box is rated at 600GPH you wouldnt want to use a return pump that flows 1000GPH so taking into account the head height loss you would want a pump that flowed about 500-550 gph. i use 1200GPH overflow boxes and my return pumps at 1000GPH at 4 ft head height.

hence the term wet/dry filter no all the drawers in a diy are NOT under water. you can have ceramic noodles in the bottom drawer under water and that works fine but bio balls/ plastic scrubbies you dont want underwater you want the water to drip and trickle on them and flow down thru them.

i would use foam/ poly floss in top drawer middle drawer i would fill with plastic scrubbies/bio balls either or both and bottom drawer ceramic noodles.

i go to the 98 cent store they sell different sizes of trays/baskets with holes already made all along the botton and sides i use this to hold the poly floss and makes cleaning it out simple and fast just take it out of the cabniet drawer dump it replace with new floss and pop it back in drawer takes like 2 minutes to do. take your empty drawer with you and find a basket/tray that fits it they have alot of different sizes to pick from and you cant beat the price 98 cents

return tubing depends on the pump you use most of mine use 3/4 inch vinyl tubing and my overflow boxes use 1 inch. yes you can make spray bar returns with cheap pvc parts from home depot etc.

good luck and have fun its a very simple and cheap DIY and works excellent. WALMART has the 3 drawer file cabniets on sale now for 7.00 at my local store maybe yours have them on sale now for that also. I always keep a few on hand.

 

[drdud]

Thanks for the reply. Very good points. I know the capacity of the overflow system is the critical point since you can only filter the volume of water that is capable of being removed from the tank. I am looking for any guidance or rules of thumb regarding the turn-over rate of the the entire system. I figured that if I know the flowrate I need, I will get/make the matching overflow box. I must have asked it backwards.

Anyway, if I run ceramic 'noodles', do I really need the second type of bio filter? (scrubbies or bio-balls).

When you say "98 cent store they sell different sizes of trays/baskets with holes already made all along the botton and sides i use this to hold the poly floss", now I envision a bowl like a sieve. Man, how simple. Pull out the drawer, swap floss, replace, enjoy.

When this type of system is running, do you change how you do water changes? I envision vacuuming the gravel as before, but adding water to the sump while vacuuming. The level in the tank would remain constant. Right?

Starting to look forward to this.

 

[RodInCALIFORNIA]

i run a 3 drawer so top is filter floss middle is scrubbie/bio balls bottom is ceramic noodles no you dont have to have both but i like it this way but you can do it as you prefer.

yes thats the idea of the 98 cent store plastic strainers for the poly floss.

i try and turn over about 10X a hour and i still do weekly water changes. and yes the sump will feed the water evap. and you add water to the sump to keep it at a constant level i add water maybe every 5 days or so.

 

[RiVerfishgirl]

1) Is there a rule of thumb for what the desired flowrate of the pump should be? Is this based on a desired number of water volume turnovers in the tank over time?

You just don't want your pump to run more GPH than your overflow can handle. Otherwise it's just a case of how much turnover you want.

2) Can I keep most of the drawers under the water line

The media can be submerged but it would then not be a wet/dry. The point of a wet/dry is that it oxygenates the media well, allowing for better bacterial growth. You will still grow biological bacteria when submerged, but it will not be as efficient since the amount of oxygen directly effects how much bacterial growth you get and how well it functions.
A wet/dry will also allow for more oxygen for your fish due to the surface area of the water in contact with the air. With a wet/dry you're getting much more air/water contact.

3) How much bio filtration media is really needed? I have seen in other threads they talk about "gallons" of volume. However, I only use a few pints of ceramic beads and it seems to be fine. Is there a rule of thumb?

Basic rule of thumb is just the more surface area for bacterial growth the better. It will depend on what type of media you use since some medias have more surface area to house biological bacteria.

To get an exact calculation of how much media you need, you'd have to know exactly how much ammonia is being produced by your fish and anything else in the tank, how well your biological bacteria are functioning (which is based on how well oxygenated they are, your pH, your temperature, and various other factors), and the exact available surface area on your media (which may go down in time as it traps detritus). So you are unlikely to be able to get a good estimation of exactly how much media you'd need minimum.
I just suggest running a media with a lot of available surface area (your ceramic beads are fine) and running as much as possible.

4) I am thinking about Drawer #1 using a sponge media (probably the AquaClear sponge or equivilent. Drawer #2 would be bio media (probably the ceramic beads). Drawer #3 could be used for charcoal or other chemical media if need. Sound like the correct arrangement?

Like any other filter you probably want your course media first, then your fine polishing media second or last (like in most canister filters).

So I'd run a course media in drawer 1 (your sponge), and a polishing media such as quilt batting underneath that in the same drawer (if you run no fine polishing media you will have poor water clarity. You can run filter socks on your outflows but they tend to become clogged quickly.) and possibly more course media under that (If you run the fine polishing media directly over the holes for the "trickle" it will clog the holes), then biomedia, then chemical media if you'd like.

5) Has anyone ever used a plastic screen laid over plastic grid ('light diffuser" material we use on the bottom of the tank to distribute the weight of rocks) to make a housing for polyester floss material? I have a vision of this resting over the top of my bio filter in Drawer #2. This would be after the 'course' sponge, so it would not clog as quickly.

You can do as I mentioned above, but I don't see why this would not work also. I have not tried it but it sounds fine and I've seen others do similar.

6) I assume the tubing/piping sizes are a function of the discharge of the pump. I figure once I know the size of the pump, I can figure out the size of tubing/piping and the number of spray bars, etc.

All you want to keep in mind with tubing sizes are that, regarding outflows, you want tubing that will fit your pump obviously, and the bigger the tubing the less flow rate you will cut off.
Any angles in the tubing will cut down on your flow rate, necking down to smaller tubing will cut down on your flow rate, adding spray bars will cut down on your flow rate, and the length/height of the tubing will cut down on it etc. So you need to take all this into account when picking a pump size. If you're going to have a lot of flow loss due to all those factors then you'll need a bigger pump for sufficient turnover.

As far as tubing running from your overflows they need to be big enough to handle how much water your pump is flowing. If the tubes you use are too small then you will overflow your main tank because the water can not exit the tank fast enough.

 

[excuzzzeme]

Due to it's larger capacity, you don't need the same flowrate you would use for a HOB. Arbitrary numbers here: Hob you want 10x per hour, Canister you want 3-4x per hour, wet/dry (trickle) 3x per hour. Personally, the greater flowrate the better. By keeping the bottom1/4 in the water eliminate "dripping noises" as well as provide for anaerobic bacteria development. The top 3/4 of the bio media is the "trickle" effect aiding in aerobic bacteria development.*

I use a 1000gph HOB-overflow, 950gph return pump, 3 ft head, 4 ft spray bar. effective turnover = 600-800gph on a 100 gallon tank with a 18 gallon sump and 5 gal media container.

Filter container (top-down): top layer is fiber-floss on top of felt, 2nd layer is sponge, separator: eggcrate, 500 bio-balls in the bottom. Suspended above a 18 gallon sump. Return pump with a sponge on the intake, heater in the bottom of the sump. The fiber-floss is used to collect large particulate and the felt effectively polishes the water by collecting fine particulate.

This is far more filtration than customary but allows for overstocking. Peak stock was 4 convicts, 1 pterogolicthys gippiceps pleco, 3 copadichromis borelyi, 1 Bala, 1 large Silver Dollar, 4 Oscars. Current stock is 2 convicts, 1 Silver Dollar, 2 Oscars, 1 gibbiceps pleco.

The bottom 1/4 of the filter actually sits in the water, leaving 3/4 of the bio balls uncovered.

A salt water tank is different in that you will want the Bio-balls to actually be submerged.

Cleaning is accomplished as any other tank with replacement water added to the sump and not the tank, Occasional vacuuming of sump is on an "as needed" basis, Filtration media is replaced "as needed" and have gone as long as 3 months between changes. This is dependent on how much waste is generated through over feeding, number of fish, etc. When heavily stocked the filter media is changed as much as weekly. Sump is kept topped-off as needed.


* anaerobic mean without O2 and aerobic is with O2. Realistically, the anaerobic pulls O2 from the water column instead of the air, it just doesn't get as much O2.

 

[drdud]

More excellent points to ponder!! Thanks for the replies.

As far as flowrates, sounds like you are getting 6-8 turnovers every hour. That really helps me out. I really appreciate the numbers on media and sump sizes. This gives me much better idea on what flowrates I need to target, based on something that works. I am really curious to see if others use similar sizes / flowrates. It seems like the more turnovers/hour you have, the better filtration. However, too high of a flow rate would make the tank more like a raging river than a rift lake. I am really looking for what that balance is and anyone's experience. I read in another forum that 8 turnovers per hour is good. Now I hear that again, which makes me think that is probably a good target. Concept is in my head. It's time to start think specifics.

One other question: The overflow box is set-up to 'skim' the surface of the water (to maybe an inch or two from the surface. My HOB pump suction draws from 8-10 inches from the surface. Does the overflow box tend to ignor the bottom portion of the tank and the heavier 'solids' that accumulate in the bottom? I know that no filter will replace regular gravel/substrate cleaning, but do the solids tend to collect more?

 

[RodInCALIFORNIA]

It will tend to collect on the bottom but if you add a powerhead to the bottom of the tank it will 'stir' up the solids into the water column and the skimmer will catch it BUT your right nothing replaces weekly maintance. Maintance is just one of those things you have to do if you want a successful aquarium, no matter what type of filter system you use.

 

[nomommythatsmyfood]

you sound like you have it pretty well planned out...I am attempting to make my diy filter...but just for my 20H tank...until I can get a real filter...I looked on here, Monster Fish Keepers (the sister site) and you tube...found tons of info...and its nice on youtube sometimes the person will show you step by step...good luck!!

 

[drdud]

Meag - I saw your other thread and the links. Some good stuff. That two liter bottle looks like a temp solution for a small tank until you can get something with a smaller footprint.