Sand maintenance in a large tank

[jccaclimber]

A year or so ago after being in the don't mess with it camp I converted to the clean the sand camp. So far the biggest tank I've done this in is a 210. The layout is such that most of the sand is accessible, and this works well.
Currently I'm running a 126" x 32" x 34" reef bare bottom. I'd rather have sand from aesthetic perspective, but am moving soon and so don't want to mess with it twice. Post move I plan to add a couple inches of fine sand.
Recently I went to vacuum the bottom (through a filter sock in the sump, no WC on this tank), and to no great surprise I can only access perhaps 70% of the floor. That's with sticking a suction hose a foot or so in to all sorts of areas I can't actually see. Once this has sand that isn't going to be practical, and I'm guessing 50-60% of the sand will be inaccessible by practical means. How do you handle this?

1) Build a wall so that sand doesn't get more than 6-12" past the rockwork where I can't reach. I don't think I'll like the look of this, and sand will long term make it over the wall anyways.
2) Plumb in a closed loop system so that I can periodically blow the sand back towards the front from under all of the rocks. This seems pretty risky, and also pretty inconvenient.
3) Hope that cleaning the 40% to 50% that I can access is enough, and hope that the section 20" to 30" from the nearest accessible area doesn't become a time bomb in 5-10 years. This also seems iffy.
4) Get a ton of cucumbers, sand sifting stars, etc., and hope they diffuse the gunk to the front where I can access it.
5) Changing my rock layout so that I can access more areas is not something I am willing to accept.

Any ideas that don't include learning to go diving in my tank?

 

[Darsh]

It it were me, I'd choose a combination of 3 & 4

 

[m0jjen]

i would skip the sand shifting starts. They consume all fauna in the sand if they are many enough. Cucumbers seem to be a solid choice tho

 

[Mariette]

Yup. 3 and 4. In a 210g, I’d assume there’d be plenty for a sand sifting sea star but I do hear they have a tendency to strip a tank clean and slowly starve to death. So I dunno. But definitely lots of CUC. Why do the work when you can get others to do it for you lol

 

[Jon Fishman]

I would build up an acrylic island 4” high or so, for the entire tank........ leaving a 1’ or so (or less whatever you prefer) “moat” around the entire perimeter of the tank..... put all of your rockwork on the acrylic stand, and fill the the moat with 3” of sand. It would be like a 360 degree drop-tank.

It would be unique......sorry, I come up with crazy ideas

 

[Phil D.]

If you can find one, I have a Marineland Magnum hang on the tank filter with a vacuum hose attachment that I attach a gravel vac to and vacuum the sand with. Works great and I can get to 90% of the sand bed.

 

[ReeferBud]

I use a combination of #3 and #4 on my 450 gal.

I tried to arrange the aquascape so that I maximized the “accessible” sand and I religiously stir up the sand every week to keep it clean and aesthetic (which is why I have it in the first place).

I’m not sure fine sand is the best choice for what you’re trying to do though. I went with aragamax select.

 

[Darsh]

I would build up an acrylic island 4” high or so, for the entire tank........ leaving a 1’ or so (or less whatever you prefer) “moat” around the entire perimeter of the tank..... put all of your rockwork on the acrylic stand, and fill the the moat with 3” of sand. It would be like a 360 degree drop-tank.

It would be unique......sorry, I come up with crazy ideas

I wanna see that haha

 

[roberthu526]

I just vacuum what I can reach. I don’t think you need to worry about the rest. Many people never clean their sandbox and their tanks do just fine.

 

[jccaclimber]

I’m not sure I’m willing to go through with it, but I do like the idea of the filler. I’d just fill the areas that I know I won’t be able to reach, and I’m guessing there are cheaper fillers than acrylic, but it has some upsides.
I think walking off then putting in something to blow out those areas might be a better use of space, but it isn’t like I can see much of it.

I feel like sifting stars have a goof survival rate, is the whole sand too clean concern realistic? I’m more worried that they would only stir the top 1/2” or so like nassarius snails.