Internal drop off idea

[fermentedhiker]

Not that I have a place for another tank right now But I've had an idea for a long time of having a medium sized dropoff tank with a dsb in the dropoff for some blue spotted jawfish, a colony of catalina gobies in the upper rockwork section along with some gulf signal blennies if I can ever find them. Obviously this would be a cooler temp tank. Reef crest has stopped making their 35 gallon aio dropoff, and all anyone carries now are the nuvo 20 gallon which is too small.

The thought occurred to me to take a used(or dollar per gallon sale new) 55 gallon. Convert one end into an AIO filter with smoked glass wall and baffles. Then create the drop off wall with another glass baffle. The drawback is that the upper side of the drop off would have to be filled with something to build it up to the top of the drop off baffle height so you could then scape up from there. I considered marine pure blocks or sand covered with a floating acrylic panel(by floating i mean not attached with cement or silicone) that had holes drilled in it to allow some water flow.

The other idea was create a horizontal glass plate for the upper platform. One way is to seal it completely so the void is air/water tight and empty just like a true drop off tank. The other would to be somehow use it as a cryptic fuge or something by forcing some of the water from the AIO section back through the void area and allow it to rise up through the horizontal plate. A bit of an elevated reverse flow undergravel if you will. Of course the problem with a wet side void is it would be impossible to clean and if a fish or invert ever found it's way into it they would be stuck there for life.

It certainly would give more volume for far less cost than a prefab dropoff.

Can someone think of a better way?

 

[fermentedhiker]

Maybe the idea is crazy since nobody has any thoughts. Wouldn't be the first time an idea of mine was questionable certainly won't be the last.

 

[theatrus]

I don't like the idea of having a totally inaccessible wet area of the tank.

Perhaps a diagram will help? How are you thinking of masking off the area you can't see?

Would using a tall tank (e.g. a 65 tall) be a better bet?

 

[dantimdad]

It's been done. Not on this forum but a while back on another one.

 

[fermentedhiker]

Me neither which is why I was originally thinking of filling the void beneath the upper section with something solid but lightweight like marine pure(just crazy expensive to do with that stuff). It's possible I could find a lightweight ceramic brick substitute that would be more affordable.

As far as hiding the void I could mask and paint it easily enough which would look much different than the black drawer or whatever the commercial ones have down there. The other option would be getting some vinyl film in black that you just wet and squeegie on. Could be peeled off if needed.

 

[fermentedhiker]

[QUOTE="dantimda

Wish I could find it. In my searches I've seen the idea mentioned once or twice but never any actual threads or description of the actual attempt.

The more I think about it the more I like the reverse flow Idea though. Have the return pump return water through a bottom plenum in the void. Stack layers of eggcrate platforms separated by pvc pipe legs to provide surface area for cryptic critters. At the top of the void section(floor of the upper section) create a rim by attaching strips of glass with silicone say 3/4-1" below the desired substrate height. Line the last eggcrate with plastic canvas or an open weave fiberglass cloth and fill full of crushed coral. I would then have a cryptic fuge and reverse flow undergravel in one, and it would be able to be disassembled if necessary(although it would not be an easy thing to take apart once the rockwork was in place.

hmmm this could actually work, and not be too expensive either.

 

[theatrus]

[QUOTE="dantimda

Wish I could find it. In my searches I've seen the idea mentioned once or twice but never any actual threads or description of the actual attempt.

The more I think about it the more I like the reverse flow Idea though. Have the return pump return water through a bottom plenum in the void. Stack layers of eggcrate platforms separated by pvc pipe legs to provide surface area for cryptic critters. At the top of the void section(floor of the upper section) create a rim by attaching strips of glass with silicone say 3/4-1" below the desired substrate height. Line the last eggcrate with plastic canvas or an open weave fiberglass cloth and fill full of crushed coral. I would then have a cryptic fuge and reverse flow undergravel in one, and it would be able to be disassembled if necessary(although it would not be an easy thing to take apart once the rockwork was in place.

hmmm this could actually work, and not be too expensive either.

Would you drill the tank on the bottom sides so your pump remains accessible? But yes, a bottom return is actually pretty nice. Way back when I ran my 55g with a spray bar on the bottom of the tank along the sandbed. It wasn't very tuneable but the water distribution from the return was very nice.

 

[fermentedhiker]

The plan was to build it as an AIO so the return pump would be in the rear section. I'll have to play around with the plumbing design to make it easily serviceable but yes it would need to be completely removable. The glass baffle that creates the AIO filter portion would end up with a hole drilled near the bottom with a bulkhead fitted that fed the plenum on the void side and had some sort of easily removable hose etc... on the AIO filter side.