How so you maintain a sand substrate?

[Drakan]

My final decision on setting up my new FOWLR tank is Sand substrate or crushed choral.

I imagine the crushed choral can be simply siphoned when doing a water change, however, I would think sand is too light to siphon.

How do you properly maintain a sand substrate?

[leebca]

You are correct. The finer the particle size of the substrate, the more challenging it becomes to 'maintain.' Keep in mind that with the 'proper circulaltion' of water inside the display system, the fine particle substrate will likely create 'dust storms' for quite some time.

For small grain size sand, I recommend first that it not exceed 1" in depth. Any thicker and it will encourage anoxic environments within the bed, potentially creating poisons to the marine life forms.

Siphoning using typical techniques of lifting substrate and detritus up a tube and having the substrate fall back and the detritus continue up the tube into a collection bag doesn't work well with very small particle sized substrates. The substrate is as light as the debris! For tank under 40 gallons I usually just 'disturb' the sandbed once a month, creating the undesirable 'dust storm' and have the circulation of the system take away the debris. An alternative for a tank between 40 and 100 gallons is to do the distrubing, but use a diatom filter on the tank to clean it up faster and more efficiently.

Much depends on the size of the display as to the approach. I like the appearance of the fine sand (powder sugar) very much, but it is a challenge to both live with, and maintain.

[Drakan]

Excellent. Thank you.

One last question. I want a blenny or goby, mostly to clean the substrate. Which do you recommend for a crushed choral substrate? any info on the comparisons between these 2 would greatly help.

Again, thank you. You and this site have made it MUCH easier for me to jump into the salt water hobby.

[leebca]

There are several species that make good community tank members, however some have 'bad manners.' I don't recommend any particular fish. However, some pick up substrate in their mouth and swim around depositing sifted sand all over the landscaping. If your landscaping and marine lifeforms are okay with this (most corals can't and shouldn't be exposed to being covered with substrate) then these kind are okay. Others scoop up the substrate and sift it right there at the substrate surface rather than broadcasting it around. Just be sure about which one you are acquiring and whether or not you can handle its habit.

Next concern is substrate size. These fish are used to substrate that is relatively small in size (1-2mm diameter or smaller). Some of the larger fish can handle up to 3.5 mm but I wouldn't go there. So whatever substrate you choose, get one that has a mix of 1-3 mm with the majority of it being at or below 2mm.