Upgrade info provided by Richard Viger.
Tidal 35
Full disclosure I do not own a Tidal 35, so I can not physically measure everything out. Based on my knowledge of the setup of the larger filters and the difference in my dimensions in comparison to the website I can estimate that these are the measurements.
Internal height: The usable height (bottom up to the spill over) may be about 3 3/4 – 4 in. Internal width: The majority of the width should be between 1 3/4 – 2 in, the bottom of the chamber may be about 1 1/2 in. The indented portion could about 3/4 in wide.
Internal Length: The length up to the indent might be about 3 1/4 in, the total internal length should be about 5 1/4in.Indent: The indent is probably about 1 in deep x 2 in wide x 4 1/2 -4 3/4 in tall.
The Tidal 35 does not have the telescoping intake pipe that the other filters do, it only uses the surface skimmer as an intake.
Tidal 55
Internal height: The usable height (bottom up to the spill over) is about 4 3/4 in.Internal width: The majority of the width is between 2 1/4 – 2 1/2 in, the bottom of the chamber is about 2 in. The indented portion is about 1 1/2 in wide.
Internal Length: The length up to the indent is about 5 1/4 in, the total internal length is about 7 1/4 in. Indent: The indent about 1 in deep x 2 in wide x 5 1/2 in tall.
Unfortunately I have not set up a Tidal 55 with BioGravel, so I can’t speak to how much I could fit in the media bag. I am currently still using one with Seachem Matrix that is on my betta sorority 20 g long tank. I think I will keep it as a Tidal 55 and upgrade the Matrix to BioGravel, so when I do that I can tell you at that point how much I was able to fit in. I would probably set it up the same way as I have the others.
Tidal 75
Internal height: The usable height (bottom up to the spill over) is about 6 in.Internal width: The majority of the width is between 2 3/4 – 3 in, the bottom of the chamber is about 2 in. The indented portion is about 1 3/4 in.
Internal Length: The length up to the indent is about 7 in, the total internal length is about 9 in. The indent is about 1 in deep x 2 in wide x 6 3/4 in tall.
I have a prefilter sponge on the bottom intake. I have a coarse sponge on the outside where the indent, where the water comes in, which measures 2 in x 6 3/4 in and is 1 in thick. I then put medium and fine sponges on the bottom, which is about 1 1/2 in thick.
I used the media bag that come with the filter (I dumped out the Matrix that comes with it) and filled the bag with BioGravel. As I said I estimate that I fit about 1,365 grams in the bag and I had to squish and squeeze the bag into the chamber. There is some space between the top of the bag and the top of the water level in the filter, so you could put a coarse sponge on the bottom under the medium and fine sponges, put more BioGravel in another bag, or use chemical filtration . It is maybe an inch or so, I rarely use carbon, so I might add more BioGravel later in I decide I need to.
Tidal 110
All of the measurements are of the inside of the removable media basket that comes inside the filter. I took a ruler and did the best I could to give you the actual measurements based on my filters. I currently own a Tidal 110 that is in use on a 29 gal tank using BioGravel.
The stated internal “height”, “width” and “length” are using the terminology that is on the website in order to try and aid in understanding. The height is the typical top to bottom. There is about an inch from the water spill over to the overall top of the media basket, which is pretty much useless as it would be out of the water, which is why I state usable height.
The length is the typical side to side, while the width is the equivalent to the depth in an aquarium, being from front to back. All of my measurements (other than the indent, which is the size sponge that would fit outside of the basket where the water enters the top of the filter and flows to the bottom before it enters the basket and flows up through the media) are taken on the inside of the media basket (hence internal height, width and length; but no internal for the indent measurements).
I have a prefilter sponge on the bottom intake. I have a coarse sponge on the outside of the indent, where the water comes in, which measures 2 in x 7 3/4 in and is 1 in thick. I then put medium and fine sponges on the bottom, which is about 1 1/2 in thick.
I used the media bag that come with the filter (I dumped out the Matrix that comes with it) and filled the bag with BioGravel.
Internal height: The usable height (bottom up to the spill over) is about 6 3/4 in. Internal width: The majority of the width is between 3 – 3 1/4 in, the bottom of the chamber is about 2 in. The indented portion is about 1 3/4 in.
Internal Length: The length up to the indent is about 8 1/2 in, the total internal length is about 10 1/2 in. Indent: The indent is about 1 in deep x 2 in wide x 7 3/4 in tall.
As I said I estimate that I fit about 1,911 grams in the bag and I had to squish and squeeze the bag into the chamber. There is some space between the top of the bag and the top of the water level in the filter, so you could put a coarse sponge on the bottom under the medium and fine sponges, put more BioGravel in another bag, or use chemical filtration. It is maybe an inch or so, I rarely use carbon, so I might add more BioGravel later in I decide I need to.