Switching out my substrate... All advisors please chime in!

[Cris007]

All your good stuff came from your rocks. Didn't you just post on how you get cyano outbreaks and algea on your crush coral and you can't seem to keep nassurus snails alive. Shallow sand beds r detritus trap meaning they can not sustain as much beneficial micro fauna as a DSB. Doing the change slowly and carefully is easier said than done and will be more stressful on the inhabitants and owner.

 

[saltwaterinbrooklyn]

ok well let me give you guys some insight on my situation, i have the following

54 corner bow front tank
itech skimmer with a external overflow, tank is not reef ready
no cover so working on it is a sinch
and my rock work is front left and right following into rear corner and rising towards the back, i totaly dont mind leaving some crushed coral in there i just want at least 75 to 80 % sand so i can get some nice sand critters in there and i would prefer not to remove things if i dont have to , even if crushed coral remains unders the rocks and behind the rock i dont mind that at all , but all the front and sides i want to redo with sand and a bit more sand than i have of coral now, which is about only 2 inches.

 

[saltwaterinbrooklyn]

and as of now i want to thank all of you for taking the time to help me figure this out , i really appreciate it.

 

[basiab]

If you leave crushed coral in there the sand will sink into it. So that is not a good option for the long term.

 

[Cris007]

If you leave crushed coral in there the sand will sink into it. So that is not a good option for the long term.

+1...lol

 

[Imbarrie]

The crushed coral substrate is, in fact, smaller rocks. To say all the life is in the live rock and not in the CC is confusing the matter. The gaps in the CC trap detritus and food so there will be life growing in there consuming the food. Bacteria and other types.
When you remove this and add sand gradually this life will migrate over. If you are careful there will be minimal mixing and you should be able to remove all the CC.
However, it is important to note if you do mix the two in some areas, the sand will fill in the spaces between the pieces of CC. This will prevent the negative aspects you are referring to with having the CC in the first place.

There are many causes of cyano and to attribute this to CC is too assume too many things.

 

[bizzarro]

I just vacuumed out 1" crushed coral . I don't plan on using any substrate going forward.

I did this in 3 phases on a 29G because the amount of water I used each time in a 2 week period. I drained out 3-4 buckets worth each time excpet for the last time. The first 2 times, I vacuumed all the substrate that wasn't under rocks, I did one half then then other half. The last time I vacuumed under the rocks and moved it then.

I think the hose I use was .5" ID so it can suck out smell shells w/o getting clogged. I got it HD. Just carefully go through the substrate so you don't kick up the debris that's stuck in it.

If you have a fine filter sock, you can direct the siphoned water into it and re-claim the water.

I have easy to keep corals so they didn't seem to mind the detritus swirling after each change but they are extending more now and less HA but still get it.

 

[motortrendz]

if you have only 2 in of crushed coral y dont you leave half of it abt 1" and then put and 2" of fine sand over it, yes some will sift down into the crushed coral but most will stay over it, this will also give you a more natural sandbet giving the denitrifying bacteria both areobic and anerobic areas to work properly..

just a thpught, ive dont that in most of my systems from the get go, heavier crushed argonite and then a fine sand over top.. i never had any problems the only time ive had the lower layer show thru the top is when the powerhead is making the sand shift and creates small sand dunes, once i adjusted water flow its been fine..

 

[tomtoothdoc]

i vacuumed out about 1/4 of the sand with each water change. some will remain in area you're unable to reach....that will help "seed" the new sand. after the tank is "bare bottom", at each subsequent water change, i add 1/4 of the sand. shut off all flow, use a chinese soup container filled with sand and water, and slowly pour out at the bottom of the tank. did not lose any inhabitants nor noticed any cycling.