Changing sand in existing setup

Okay, SOOO, quikrete doesnt make reef sand....Let that be a lesson learned by yet another person. My tank is just NASTY.

The water tested great except for silica wasnt tested and im sure with the diatoms its high. Anyway I got myself some nice crushed limestone sand. It has some rock in it, but the biggest rock are about the same size as the bigger aragonite chunks I see in a lot of sand and it only makes up maybe 20% of total volume. I tested the sand w/ Vinegar and it does foam up rather nicely so I think I've got usable stuff after a good rinse of course.

That said, how do I go about changing the sand. I currently have about 40 pounds of live rock, 2 damsels and a 3" engineer goby. My "alternate containment" options are my 5 gal QT and I have a 10 gallon plastic tub. I was thinking of putting the rocks in the tub, putting the fish in the QT, getting the old sand out, put the rocks back, put the sand in, and then after another day or so put the fish back in.

Any other methods?

 

stirring existing sand will cause toxic stuff to rise into water column. Yes I would take fish out and rock out. and then most of your water. It will stress fish a bit but better then exposing them to the toxins in sand. good luck on the change.

 

+1

I used this method when I switched from crushed coral to sand. Managed to salvage the water all the way down to about and inch above the sand.

 

K so I'm going to put my rock in a 10 gallon rubber made, fish into the 5 gallon, and then im going to stick my return pump into the tank to put the tank water into a BIG rubbermade tub. When there is about an inch of water ill be scoping out the sand, then try to remove as much of the last inch of water with the sand to remove as much bad stuff as possible (mind you this tank isnt even 3 months old, I tire of diatoms quickly).

Can anyone give me an idea of crush limestone sand is okay? It fizzes a lot with vinegar so i'm pretty sure its good calcium sand. There are some rocks (crushed coral size) so I'm going to screen them off and either not use them at all or if the volume of sand available to me is less than I'd like I'll put some of it (1/2 inch maybe) down before the rest of the sand.

If there's a better way let me know I'm new at this stuff, hence the quikrete (to me sand is sand is sand heh not no more).

 

Plan sounds good, just make sure to manage the temps.

Well, I'm not quite sure on the leaching qualities of limestone sand. Do you know if it's free of heavy metals? You can get some great sand from Home Depot (not joking).

 

The only problem with taking it out all at once is your going to lose a lot of your bacteria. You may see a mini cycle. So test the water for awhile and watch the levels.

 

True. I saw a very minute spike in ammonia and nitrates for about two days before everything evened out again.

 

I can handle a minute spike. My sump is full of bio balls and rubble (like 15 pounds rubble) so I think I'll have enough bacteria. Plus keeping the rocks wet the whole time (like maybe a minute out of water in and out) so I wont lose it there, just the sand itself... so shouldnt be much issue. Also I dont anticipate getting it ALL out, so there will be some seeds.

 

if its fine sand you can use a tube like off your siphon and take the siphon off and just use the tube without the siphon part. thats how we do it at my store. just siphon it out. it works really good! and it doesnt stir it up much at all!

 

or if its like very fine crushed coral. just no big chunks cause it can claug the tube.