Hiding places for a large fish

[dendro982]

Hello,
I have a baby fish in quarantine tank, that will be transferred to a 90g tank, with a larger tank due within 1 year (based on previous experience with this kind of fish, in this tank. Lost it to unrecognized in time infection, more than year ago).

New tassle filefishes, Chaetodermis:

And new baby Antennata lionfish (old Mombassa jumped off unnoticed it time 1.5 yrs ago):


90g tank:
was disassembled thoroughly cleaned, dried and now is ready for a filling.
Additional water cleaning steps (25 micron mechanical filtration), UV sterilization and shock absorber - fluidized bed on power backup. Maybe intermittent ozone. Weekly water changes and doubled amount of carbon. Amount of water, pulled through filtration will also increase - to 10x tank volume per hour.
Correct me, if something seems wrong.
This is intentional overkill approach. Tank will have 250g rated skimmer, ASM G-3, and another similar skimmer could be added (Turboflotor 1000, 250g rated too).

I currently stuck with aquascaping, balancing swimming and hiding space. Particularly what kind of hiding places for filefish, when it become large.

Below are photos of what I tried with the first fish:
for 6 months old file, terrace/ledge and cave:



I was advised to imitate basket by sparing rock structure.


Fish is inside.

[dendro982]

As fish grow, it needed more free space.
Aquacaping was flattened:

As corals started to grow, even not too bad looking:

This is 1.5 yrs old fish:

No hiding space, except behind the left group of rocks.

I know, that 90g tank will be small, already looking for another.

Any advice on kind of hiding places for this fish and where - corners, top/ledge, wide gap between rocks as for triggers, should cave be closed from 3 sides or from 2 sides will be enough - for easier entering and leaving?

Thanks.

[leebca]

I think the layout is fine for the fishes you've mentioned. Not all marine fishes will want or need a place to hide. Most will require a place to 'sleep' however.

They generally prefer places that are tight to hide in, not wide open. So suit the structures (like caves) to be about the size of the fish that would use it.

Although caves are a 'cute' looking structure to humans, few marine fishes like them. They prefer holes in the aquascaping -- like a pile of rocks with many open spaces -- sort of like what a condominium might look like after an earthquake. This is what is referred to as 'bolt holes' in the landscaping.

[dendro982]

Thank you! I didn't think about it that way.
But should the hole be open only from the one side, so fish have to move backward, when leaving sleeping place?
How much longer than fish it should be?

[leebca]

An optimum (IMHO) design would be a couple of inches from the back wall. This allows for circulation behind the landscaping, over and around it. The opening in the back will be open to bolt holes on that side, too. Rock hap-haggardly piled will provide bolt holes that are open to the rear area, from the front bolt holes. Although the holes may not appear to go straight through, the fish can find its way in the rocks to get to the back of the tank, from the front bolt holes.

I hope the above is clear.

[dendro982]

I have a problem visualizing it ;;
Will it be:
1 - rock piles, forming more or less solid rock wall in 2" from the back tank wall,
2 - or eggcrate or QuickCrete flat rock wall in 2" from the back tank wall, with rock piles, leaning against it?

The big fish will be 11" long (including tail fin, ~9" without it) and 6" high, 1" wide belly (2.5" with side fins).
It was able to freely turn at full speed in 18" wide tank, and pass behind the rock within 4" from back wall, but open from both sides for direct swimming through the passage.

Convenient aquascaping is my weak side, unfortunately, but I'm willing to learn

[leebca]

1. Is right with the exception of the 'solid' wall. The solid chunks of rock and/or coral skeletons form a network of holes (bolt holes) in the (not solid) wall of rocks, holes large enough for the fish to swim into and through to the rear of the tank. Within the 'bolt hole' it would be okay for the fish to have to make minimal turns (a slight maze) to get through the rock pile to the open back space.

You can even add appropriately large diameter PVC tubing in the rock works to 'guarantee' the hole goes through the rock pile to the rear, then hide the pipe by placing rocks around the front end. This is assuming the tank is against a wall and won't be viewed from the rear. The minimal areas of PVC pipe showing will blend in soon enough as they become encrusted with coralline.

I bought many of those plastic 'sewer pipe' ornaments and put them into my rock works. They were of differing sizes (diameter pipe) to accommodate different heights of fishes. Much to my surprise I learned from observation the fishes liked going into those pipes more than into rock-formed bolt holes -- when they felt they had a choice.

With landscaping you have many choices. Above is given the general title of the reef pile or volcano effect. Others can be shaped like a horseshoe, or two split piles, or a pile on one side or end of the tank then tapering down in height to the other side. Just use your imagination. Don't have to do what anyone else has ever done before. Try to get to stores and also other hobbyist's homes to see actual setups. There are some books that are particularly good on landscaping ideas. You may want to start with some of the books listed here: Marine Aquarium Books & Reading

The larger (diameter or height) the fishes are, the larger the holes and more open the landscaping will be. Some of the marine fishes require more hiding places; other require more open swimming places. The best thing is to read up on the kind of fishes you want, and design the landscaping to their need(s).

[dendro982]

Most grateful for your help! This approach is completely new for me, I'll try that.

I regularly attend four stores and, apart from twice larger tanks, their are open concept with no hiding places for a large fish at all. Tanks of other hobbyists (photos on the web) are more tang and angel oriented and either three times larger, or contain juvenile fish. Most experienced tassle filefish keeper, that I know - her tassle was 8 years old, who posted information online, posted only photos of 3x larger tank, not the small 90g, alas. But I'll take a look at the recommended books too, at first possibility, thanks for the link.