In situ substrate swap

30g rimless, square tank from Mr. Aqua. Photo courtesy of the author. 

As of yesterday, I had four tanks (75g, 2x 20g long, and a 30g square) that contained aragonite sand substrates. Suffice it to say that I’m not happy with any of them. I have two other tanks that contain pool (silica) sand (75g and 55g).

Over time, I have honestly felt like my fish are more active and look better in the pool sand tanks. The tanks with aragonite are relatively new (~8 months) and I have had more fish problems with them than with pool sand tanks. Maybe it’s a coincidence. Maybe it isn’t.

Recently, I have been operating on the assumption that it’s not a coincidence. Therefore, I decided to replace all aragonite with pool sand.

That process began today with the 30g square tank (see photo above). If you recall from yesterday’s post, this tank has not been very kind to its occupants – Lamprologus ocellatus. Maybe it was the occies themselves, as I alluded to in that post. My gut tells me otherwise.

Regardless, I decided to remove all the aragonite from that tank today and replace it with pool sand. I did that in situ – meaning I left the sole occupant (a male occie) in the tank while I made the change. I did that mostly because the tank contains about a dozen shells and I wasn’t sure which shell he was in. I tried to find him but I couldn’t. I could have removed all twelve shells to a container while I did the change, but I decided to just move the shells around while I did the swap.

There wasn’t much aragonite (maybe 1/2 – 3/4″ total depth) in the tank, so it didn’t take long to scoop it all out. I replaced it with only about 1/4″ of sand.  In my experience, Aragonite sand creates a very milky-like cloud when disturbed. So scooping out what amounted to about a gallon and a half of aragonite really clouded up the water.

I filter the tank with a Sicce Whale 500 canister filter (yes, that’s lots of filtration for a 30g, but I adjust the flow rate so it’s not a whirlpool), which I left running while doing the swap. I also employed one of my DIY bottle filters that I filled full of floss to help catch fine particulate that got stirred up. I knew that the two together would minimize the cloudiness.

Afterward, I cleaned the Whale thoroughly. The entire process, which took about an hour, also resulted in a 50% water change. You can see from the photo above that the tank is still a bit cloudy after about three hours. I removed the bottle filter once I filled the tank up, otherwise most of the cloudiness would probably be gone. I don’t have much fine mechanical filtration in the Whale media baskets.

It should be pretty clear by tonight when I feed all my tanks. We’ll see tomorrow what the sole occie thinks about the new substrate. I doubt he’ll come out tonight after I turned his world upside down for a while.


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