[cfish]

I have a 15 gallon and 20 gallon high, both moderately planted, and I'm trying to sort out which plants will do well under the AC30 HOB filters.

When running full tilt on either tank, they seem to move too much water to grow anything directly under them. So, that's where some of the hardscape is strategically located for now. I've ready plenty of posts where people are using HOB filters with heavily planted tanks, and I'd really appreciate some advice on how best to situate plants (where and what type) near the outflow that will look nice and not get completely knocked down by the current.

I'm a fan of stems/tall plants toward the back to obscure the filter intake, but perhaps I'm limited to lower-growing options. I'm just hoping that some of you experts can offer a few words of advice.

Thanks in advance.

 

[Sharkfood]

If you keep your water level high, up to the filter outlet, the flow tends to get directed across the surface rather than straight down into the water column. This will keep the outflow from battering the plants underneath.

 

[TactusMortus]

I know I have heard of some people putting small sponges where your filter spills out at.

 

[lauraleellbp]

Bolbitus loves flow so would be a good plant to put directly underneath an HOB return. Can get tall, so might be better for the 20gal tall than the 15gal.

Crypt spiralis and balansae have done well for me in high current, as long as the current doesn't scrape them against driftwood or rocks. Chain swords/Sagittaria are some other options.

Anubias probably wouldn't care, either.

 

[madness]

I have driftwood with anubias or moss in front of the overflows on my AQ filters in two different tanks but it is glued on stuff in both cases so I don't have to worry about knocking anything loose. Haven't really given it enough time to figure out what impact it will have on growth.

I had a ceramic 'mat' of java moss from Petco that had done nothing at all for maybe 6 weeks that I moved to a little 10gal tank and propped up against the glass directly in front of the AQ50 outflow and all of a sudden it took off and started growing. No idea if it was the dramatically lower light or the flow that improved the health but both tanks were inert substrate and the same ferts dosed (if any). If nothing else atleast the flow keeps the java moss clean.

 

[DogFish]

You could take a CD case cut a pc of clear or black plastic from it and glue it to the bottom of the overflow to act as defuser to spread the water out over the surface.

 

[AirstoND]

Other DIY

Cut a plastic water bottle in half (twice) and use a shoelace, kite thread, or fishing line to tie around HOB output. A filter pad or plastic mesh from arts store works also.

 

[cfish]

Thanks to all for the solid advice. I'll likely try some of the plants lauraleellbp recommended, and failing success may opt for some of the DIY solutions to diffuse the flow a bit on the 15g.

The 20 high is about to be decommissioned in favor of a 40 breeder (yup, I've got the bug) so you're likely to see a few questions about the new setup as well. No HOBs to worry about on the new one as I'm switching to dual canisters.

Thanks again!

 

[tetra73]

I use a Marineland Emperor 400 on a 40g tank. The filter is rated for 80g. What I did was that I used 2 rectangular plastic cutouts about the size of the water outlet tray. I managed to put them over the 2 outlets so that water is actually being pushed downward. So you get the downward water flow. Then, I discovered that I wasn't getting enough water surface moment to deal with the bio film. Then, I cut slots on the plastic cutouts to allow some water to flow outward while some downward.

Here is the photo of my tank and you can see the plastic over over the water outlets.