Using Sand in a Freshwater Aquarium
So You Wanna Use Sand...
As a freshwater aquarist, I have always envied the colorful, sandy-bottomed tanks kept by marine hobbyist. Outside of having a cichlid tank (thanks but no thanks), I can't emulate the colorful beauty of ocean fish. However, I can have that handsome sand settling across the bottom of my freshwater tank. After mulling over it for a year or so, I decided to take the plunge and convert from gravel to sand.
Why Use Sand in your Freshwater Tank?
There are several reasons to use sand in your tank:
- Sand is a soft substrate that bottom feeders (like catfish and freshwater eels) absolutely love. It mimics many of their natural habitats and it is more gentle on their exposed bellies.
- Unlike gravel, sand gives you an even surface without cracks and gaps. This comes in handy because excess food and waste will simply sit on top of the sand. With gravel, waste and food will literally fall through the cracks.
- In my experience, it is easier to get a good freshwater plant population growing and thriving in sand. When I used gravel, I still had to add a layer of sandlike substrate to give the plants more nutrients. Just be sure to gently "massage" the sand near the roots to prevent compacting sand from blocking your plant's root growth.
- Sand is beautiful to look at and its' generally light color actually makes your tank appear brighter without any additional lighting.
What substrate do you prefer?
Improve Your Aquarium
Okay, I'm Convinced...How do I Add Sand to My Aquarium?
Adding sand is pretty easy to do (although it can be time consuming, especially if you are converting an existing tank). There are a tons of different sand that can be used in your freshwater tanks....Tahitian moon sand, beach/river bed sand, pool filter sand, playground sand, etc. Unless your fish prefer a high pH, do not use crushed coral or argonite sand. If you choose to use playground or beach sand, it is often recommended that you first boil your sand.
Personally, I chose to use pool filter sand. I'm from the school of thought that pool filter sand is a bit cleaner than playground sand (depending on who you talk to, this opinion may vary). However, it is still extremely cheap when compared to the actual "freshwater sand" that is found at Petco and the like. I found 50 pound bags for just over $11 at my local pool supply store. If you live in a warmer area you can probably find it even cheaper.
I had gravel in my tank when I decided to convert to sand. I did not have a secondary tank big enough for all my fish so I caught them and put them in heated 5 gallon buckets during the conversion. The water in each bucket was water drained directly from the tank to the buckets. I covered each bucket with a towel to prevent drafts and fluctuations in temp (this also prevented jumping fish and created a darker space to help reduce the fish's stress levels). After getting the buckets set up, I continued to drain water from the tank until I had removed about 70% of the water from the tank (by this point my filter, heater and air pump are all turned off). Once I got the fish out, I took the opportunity to clean everything thoroughly. I removed the heaters and rubbed them down. I removed all caves and decorations and sprayed them down with clear water. I removed the hood and light strip and wiped away the mildewy goo along the edges. I even wiped down the airline tubing. Using a soft edge dustpan I scooped the gravel out of the tank into some old Rubbermaid totes (which we used in a drainage area outside later in the week).
While I was cleaning the tank and removing the gravel, I was also multitasking by cleaning the sand. To clean the sand, I filled a few clean 5-gallon buckets with the new sand (about 3/4 full) in my driveway. Next, I took a garden hose and put it in each bucket. Before turning the water on in the bucket, I would bury the hose in sand at the bottom of the bucket and then use the bucket's handle to further secure the hose (just fold the handle over to kind of pinch the hose to hold it in the bucket). Once everything was secure, I turned on each garden hose and just let it run in each bucket. At the start, you can expect the water to look extremely cloudy. The water will overflow the bucket, taking with it floating debris. Use your hand to stir the sand up from time to time to make sure all of it is getting clean. I would generally let each bucket run about 20 minutes or so. At the end of 20-25 minutes, the water in the bucket would be flowing crystal clear. Once the water is absolutely clear, the sand is clean and you can move on to cleaning more sand. Just set your clean, drained sand aside...I did this with more 5 gallon buckets (yeah, I know...I own a lot of 5-gallon buckets). My cleaning cycle took about 20 minutes, but I have heard of it taking 45 minutes to an hour...it just depends on how dusty and dirty your sand is to start with.
Once I had my tank clean, I used a plastic measuring cup to dip the clean sand into the tank. I did this until I had the bottom of the tank had about 1'' of sand sitting on it. I also took this opportunity to add suction cups to my air pump tubing and bury all air stones (gravel holds these things down better so take care to get it right when you are setting up...use anchors if you have to). I dipped the sand out into the tank because I was attempting to stir up the sand as little as possible. After I got the sand in and returned the tank decorations, I filled my tank back up with de-chlorinated water. Once I finished filling the tank, I turned my heaters back on. My water was still extremely cloudy at this point because as careful as I was, I still stirred up the sand in the tank. I waited about 45 minutes and it appeared that the majority of the sand was settled again. After the sand settled, I turned my filters and air pump back on. After another 30 minutes or so of allowing the remaining sand to settle, I checked the water parameters and temp. I tried to match them as closely as possible with the water in my 5 gallon buckets where my fish were waiting. I then started adding my fish back to the dark aquarium (no lights since they had been sitting in a dark bucket for several hours at this point...my attempt to reduce their stress as much as possible). After adding the fish back to the aquarium slowly, I considered the project a success and went to bed!
Anything Else I Should Know about Sand as a Freshwater Substrate?
Well, I am glad you asked. As excited as I am about my sand, I must admit there are a few possible snags to this substrate:
- You should not use argonite/crushed coral sand as it will raise your pH, which many fish will not tolerate. For examaple, cichlids generally won't mind the higher pH but angelfish (who prefer softer water) would not tolerate it.
- If you are using sand, be sure to disturb the sub-levels of sand regularly (or have a burrowing crew like Malaysian trumpet snails or tire track eels). Sand compacts over time and creates pockets of gas that will kill your fish if the gas-filled pocket is opened. Prevent the gas from building up by raking through your sand each time you clean it. This generally only adds another 2-3 minutes to my regular cleaning routine.
- Light colored sand shows every piece of uneaten food and fish waste. You must stay on top of your cleaning routine to keep it looking pretty.
- Sand is very fine and if stirred up too much it can get sucked up into your filter and damage the impellers. Once the impellers are worn out they must be replaced (if you can find the parts) or replace the filter. This can be expensive.
- Sand is basically crushed rocks/sediments. These fine particles can and will scratch the surface of your tank. Be careful when cleaning your tank not to trap grains of sand between your cleaning tool and the glass....otherwise, you will see little scratches everywhere you unknowingly scraped sand against.