What’s old is new again

[Paul]

I’m setting up a 10 gallon for some smaller fish and I’m considering using an under gravel filter to maximize swimming area. I used one when I was a kid on a 20 gallon with good success. Any thoughts?

Edited November 24, 2020 by Paul

[ange]

I haven't used once in years but if it's good enough for Murphy it's good enough for me.

[Andy's Fish Den]

I'd go for it. I used them for years and never had problems, even grew loads of plants, especially jungle val and sword plants in tanks with them.

[lefty o]

they certainly work, just not the latest and greatest. 

[DougR]

I have both an canister for main filtration and an undergravel filter for the fertilizer and water polishing in my planted 45 gallon tank and love it.  Aquarium Co-op has a video on the undergravel and that is what got me thinking of using one for my planted tank.  IF you are going to gravel vacuum like you should regularly the main complaint about the waste going to the gravel becomes more good thing as to me it is easier and cleaner to gravel vac than to clean out the HOB or canister foam of the food and waste.  I mentioned water polishing or making it crystal clear and the undergravel does a better job for me than filter floss.  For testing I was just turning off the power heads that I use on the undergravel.  When its on my plants grow way faster with just liquid fertilizer regardless of type.  I am using CO2 for the plants and that is the reason I am not using airstones and an air pump to run the under gravel.

 

Looking at a new tank and wondering if anyone has thoughts on making one from scratch as I want to do a 48 by 24 tank and not seeing one made for that size.

[Ken Dyer]

2 minutes ago, DougR said:

Looking at a new tank and wondering if anyone has thoughts on making one from scratch as I want to do a 48 by 24 tank and not seeing one made for that size.

Believe most of the 120G tanks are 4x2x2, so if you like the 48"x24" footprint I am a fan of 120's

[lefty o]

as above 120's are 48x24x24. ive had a 120 for about 25 years, and imo when getting into larger tanks it has the right dimensions, or better stated the right aspect ration of length to depth. only downside is being 24" deep, any time you do anything with it you are pretty much up to your armpits in the tank.

[Ken Dyer]

4 minutes ago, lefty o said:

any time you do anything with it you are pretty much up to your armpits in the tank.

I may have a skewed perspective as I used to have a 150 tall, same footprint but 30" deep. After that the 120's don't seem so bad 😉 

[FrozenFins]

I've never used one before but its defentley something that I want to try. I'm intersted in seeing what others think of undergravel filters?

[Dandy Pearl]

For me, I wouldn't use one. I run planted tanks and it would be constantly worried about punching through it when inserting a root tab, planting a plant, or some other maintenance. It limits the depth (no more than an inch) of and type of substrate you use (no sand, no soil, only course gravel). You have to stay up on your gravel vac'ing or the mulm will build up and clog the filter.

I had one years ago, and found it a pain to use as gravel inevitably got under it which caused it to not perform well.

When it was time to pull it out, it wrecked the whole tank to remove.

They do work, do what you want, but some things went by the wayside for a reason.

My two cents.

Good luck with your new tank.

[Matt_]

I ran a UG filter on my first 10 gal tank in the 90s with fish only (I wish I had the Internet and LED lights back then!), and I never liked it because it takes up vertical tank space and there is no good way to clean out the mulm or anything else that gets into it (at least the model I was using) without dismantling the entire tank.  I ended up with a huge number of pest snails in there by the time I broke down the tank.  Dismantling the tank alone is a deal breaker for me now and I do not plan to run one again.  You may have a totally different experience with plants as others have pointed out.

I remember that the folks that I saw successfully running UGs back in the 90s for fish only tanks drilled the bottom of the tank and installed a drain valve so that they could clean out the filter.

I recommend a HOB filter or canister filter to save space over the UG filter if you are not using live plants.

Edited November 28, 2020 by Matt_

[Ken Burke]

On 11/23/2020 at 11:39 PM, lefty o said:

they certainly work, just not the latest and greatest. 

Well latest anyhow.  😉

[CanadaAmanda]

I am in the process of setting up a vase aquarium - it’s 10” diameter and 25” tall and I think I’ll run about 5-6 gallons of water in it.  I installed a UG filter in it, it only took 2 pieces of the bottom plates (they came in smaller pieces that fit together).  I’m interested to see how it works out!  I am wondering if root tabs are even needed - if water and nutrients are circulating down into the gravel... seems unnecessary, just use liquid?

 

For cleaning, can you run an air line tube as a siphon and snake it under the filter plates to vacuum out the gunk?

 

 

 

 

[gardenman]

"Looking at a new tank and wondering if anyone has thoughts on making one from scratch as I want to do a 48 by 24 tank and not seeing one made for that size."

Many, many years ago the University of Delaware put out a small booklet on marine aquarium keeping that included plans for a DIY undergravel filter. (The Nektonics UG filters were the rave at that time for marine tanks. If you kept marine fish back then, you needed a Nektonics UG filter.) Their homemade version of one used fiberglass or acrylic corrugated roofing panels that were cut to fit the aquarium. Then they used a fine toothed circular saw blade to cut slots in the filter plate for the water to flow through. The slots were cut across the corrugations, but just through the peak of the wave of the corrugation, if you catch my drift. Then they glued in lift tubes every foot or so along the back of the filter.  They put spacers under the filter plate to ensure there was water flow under it and there you had a quick, easy, homemade UG filter that they felt was comparable to the Nektonics.

I've been intrigued by the idea of building an undergravel filter that used split pieces of PVC pipe to create an air channel under the gravel. Kind of like a long open bottomed snake under the filter plate. In a smaller tank the airline would go down on one side of the tank into the inverted "U" shaped channel, travel along that channel to the outlet on the other side of the tank and then emerge through a discharge I like to think that would create more current under the whole filter plate and also provide more time for an oxygen exchange due to longer contact time with the water but I'm not sure if the newly inserted air wouldn't just rise above the air/water friction layer and zip out without disturbing the water under it. A way around that would be to use a long, very long, series of airstones spaced under the  inverted "U" structures to agitate the water and inject the air at the same time. 

[Tanked]

Somebody said it:  UGFs only got a bad rap because there are no additional parts to buy.  I've been using the same UGF with a powerhead and 2" of medium gravel for decades.  I've only had to replace the impeller in the power head.  Maintenance is little more than a gravel vac.  If you want to clean deeper, you can insert the siphon into the lift tube during water changes.  The fish prefer that.  The best part for me is: if you have a major substrate disturbance, the UGF has a much larger surface area for polishing the water.