Connecting a Tidal 55 to an undergravel filter, 29 gallon tank

[madmark285]

My logic for this project, I always vacuum the gravel when making water changes. So cleaning a gravel filter adds no additional work. But Aquarium Science says I shouldn't vacuum. Anyways, this now gives me the best of both worlds. I now have a low maintenance undergravel filter with a huge bio and mechanical filter and can use the Tidal filter basket for whatever I want. 

I agree with the Aquarium Science article, the arguments against UGF when using gravel substrate just don't make sense. Now using fine grain sand vs gravel is a different topic open for debate. 

Now the good news, the water intake tube fits perfectly inside a piece of 1" PVC pipe! That's makes this a easy project. The bad news, the inside dimension of sch 40 PVC pipe is not standardized. I suggest taking the intake tube to Home Depot to make sure they fit. So an easy way to make a DIY UGF filter, connect a 1" PVC pipe, 1" coupling, 1" to 1/2" bushing, 1/2" tee shown below.

I suggest only using perforated pipe on the blue pieces of pipe to get a more even flow but this is just speculation on my part. Long term the screen material may be a bad idea, it could get plugged up. Only time will tell. 

Of course I did it the hard way, I connected the 1" pipe to a small PVC box. The 1/2" PVC pipe is connected to the box shown below:

On my tank, the Tidal is mounted on the side. The long term goal is real plants along the back and side. The gravel you see is actually Eco-complete with a thin layer of gravel on top. There is 2.5"perforated  pipe buried in the Eco-complete, I wrapped screen material around this pipe. The logic here, create a slow flow of water thru the planted section which will not be vacuumed. You can't see it here but screen material covers the entire bottom.

Note: the round 2" piece of pipe is for another plant ie: a planter box. 

I used my table saw to cuts the holes in the shown below:

Of course you can just drill holes instead.

And here the final results:

I did a simple water flow test with the Tidal connected to the UGF vs unconnected, I measured little difference in flow. Note: I did block the skimmer water intake on the bottom with silicone. 

I am quite happy with this project,. Being semi-retired, I need aquariums that can run with little supervision for a couple weeks at a time in case my wife and I make a trip. I can use the Tidal just as a water pump and this should be a very reliable system requiring little maintenance. I think this is a better option than using power heads, I can still use the Tidal as a filter. 

Next mod for this system, an effective way of putting Polishing Felt Filter Pad 100 Micron in the Tidal filter chamber. Shown below is a air filter:

With the zig-zag pattern, they can double the surface area of the filter material. How can I do the same with the felt polishing material? 

   

 

 

[madmark285]

One more issue with this system. The Tidal mounted on the side created a serious current in the tank. My original plan was to create a river tank but that didn't work out. Connecting the Tidal to an undergravel filter has reduced the current, I can now run the Tidal near full output. 

[Galabar]

Looks great.  I also created a PVC UGF (run with powerheads).  It has been bullet proof.  I do vacuum the gravel every once in a while.  However, I'm not sure I need to.

 

[madmark285]

On 3/16/2024 at 6:50 PM, Galabar said:

  I do vacuum the gravel every once in a while.

To be fair, the author of the Aquarium Science article included:

A Caveat

Undergravel filters have not been widely tested as a filter in the aquaculture industry, The limited testing done on gravel filters for aquaculture was “all over the map” due to the very high loading of commercial operations. So one is left with common sense and anecdotal “testing” as the only sources of information in the analysis below.

So the question of should I vacuum the gravel is open for debate. For myself, I will vacuum the open areas every water change, it is so easy with my setup. 

The debate on UGF is should be: sand vs gravel substrate. If using gravel (~4 mm in size), detritus will settle into the gravel and may require cleaning. So just put in an UGF. 

 

 

 

[Pepere]

My take is that cleaning substrate with an Under Gravel Filter is akin to cleaning out a canister filter.

Yes you are removing some nutrients from the substrate that plants can use, but you are also removing waste organics that algae thrive on as well.   
 

And plants can do just fine fir the most part with water column fertilization and inert substrate.

[OnlyGenusCaps]

That tank looks really nice, @madmark285!!!  You are always the PVC king!  If the screening becomes a problem, I wonder if Poret cut to fit in between the PVC might work better?  Not for more biofiltration surface area, obviously.  But, it would hold the gravel up, and if it got clogged, you could pull sections out to rinse them, in a pinch.  Just a through.  Like I said, it looks great!

[TOtrees]

@madmark285 when you say you covered the skimmer with silicone, do you mean the vertical slits at the waterline? Did you also cover/block where water comes in here (red arrows)?

I'd be curious to see a test of your filter with the tube from the ug grid completely blocked. I think that these filters let a lot of water in via ports other than the bottom tube, and not just the vertical skimmer slits. So I'm wondering if the "secret" or "hidden" intakes I've highlighted might be reducing the amount of draw through your ug grid, even though you have blocked the skimmer openings. 

[madmark285]

On 3/19/2024 at 4:23 PM, TOtrees said:

Did you also cover/block where water comes in here (red arrows)?

The bottom ones where the water comes in and I am not sure if that was a good idea. The silicone can be easily removed, I might open up a few slots and see what happens.

I highly doubt the ug grid will get completely blocked and I plan on vacuuming the gravel, that was the point of this project ie: I always vacuum the gravel. 

 

[madmark285]

 

On 3/19/2024 at 3:47 PM, OnlyGenusCaps said:

But, it would hold the gravel up

In the front section, the screen is glued to the top of the pipe which will hold the gravel up. In the back, the pipe is buried in the gravel. My logic here, my plastic plants prefer a slower flow 🙂 I really need to order some real plants....

This may be one of those projects where I should have just bought the plates, the Penn-Plax only cost $15. Having the Tidal mounted on the  side did make it more complicated. 

Edited March 19 by madmark285

[madmark285]

On 3/19/2024 at 4:23 PM, TOtrees said:

I think that these filters let a lot of water in via ports other than the bottom tube,

So my question here, would this concept work with an AquaClear filter? That filter may be a better option for this idea. 

On one hand, I do not yearn for the good old days of just a undergravel filter. Using powerhead just improved the flow but it was still just a gravel filter. Replacing the powerhead with a HOB filter gives you alot more flexibility for your system. 

[TOtrees]

On 3/19/2024 at 7:14 PM, madmark285 said:

So my question here, would this concept work with an AquaClear filter? That filter may be a better option for this idea. 

Simpler maybe: ALL the water coming into the ACs comes in via the intake tube, and there is no intake bypass. I don’t know about the 70 or 110 but the intake tube on the 20 & 50 mates perfectly with 1/2” cpvc tubing.