Help with newish aquarium - sand substrate

[Kelly Preussner]

I am not necessarily new to aquariums, but I’m new to using sand substrate. I have always had gravel bottom aquariums and recently decided to start a 20 gallon sand substrate bottom. I got a little heavier sand (not the real fine kind) in hopes it would be easier to vacuum which it is. I do weekly water changes & some bottom of tank cleanup with the water change. My sand bottom is looking worse and worse as time goes on and my water has never been very clear. Is this some kind of algae? My tank looks so dirty! I have enclosed pics. Today is cleaning day and it has been a little longer since my last clean (10 days). Even with my other aquariums if I went two weeks without cleaning, they never looked this bad. Before I start my cleaning today, I am tempted to go to the store and get gravel and replace the sand with gravel. Suggestions??
In my tank, I just have guppies and one Molly.
I also have two plants. I used to have nerite snails, but have not gotten them for this tank yet because I was not sure about the sand bottom - it’s very soft & I was not sure they could move along the bottom.
I should also note that all the new guppies I have purchased have died in this tank. The only living guppies I have are my original from my old tank and fry that have been born.
Ph is 8.3 (always been high)
Ammonia 0
Nitrite 0
Nitrate 5.0 (lowest on my chart)

Any help would be greatly appreciated!

 

[WhistlingBadger]

A close-up picture of the sand would help, but it looks like you've got a diatom bloom going on. Does it look like a film of brownish dust that sticks to everything, including the lower glass?

If so, take heart. I almost always have a diatom bloom when I set up a new sand tank. It doesn't look great, it's harmless, and it will go away, usually in a month or two. It's also easy to wipe off of surfaces.

By the way, nerites will do just fine crawling over sand, and they love to eat diatoms. Hang in there!

 

[Kelly Preussner]

A close-up picture of the sand would help, but it looks like you've got a diatom bloom going on. Does it look like a film of brownish dust that sticks to everything, including the lower glass?

If so, take heart. I almost always have a diatom bloom when I set up a new sand tank. It doesn't look great, it's harmless, and it will go away, usually in a month or two. It's also easy to wipe off of surfaces.

By the way, nerites will do just fine crawling over sand, and they love to eat diatoms. Hang in there!

Yes it does look like that. I have enclosed a close up picture. It seems to only stick to the sand & plants/decorations & not the glass. When I try to vacuum it, it is very clumpy. How do I get rid of it? I was debating changing out the sand but maybe I should get some nerites.

 

[Kelly Preussner]

Yes it does look like that. I have enclosed a close up picture. It seems to only stick to the sand & plants/decorations & not the glass. When I try to vacuum it, it is very clumpy. How do I get rid of it? I was debating changing out the sand but maybe I should get some nerites.

Do I try to vacuum it up? Take it out? Wash it off ornamentals?? Thanks!

 

[WhistlingBadger]

Changing out the sand will probably just prolong the problem. You can wipe off the ornaments with a clean rag. If this is indeed diatom algae, it wipes off very easily. Giving the sand a shallow cleaning and stirring it up a bit will help with the aesthetics, but removing it from the sand is nearly impossible and probably pointless. Give it time. Only bad things happen quickly in this hobby.

 

[Seisage]

I'm also currently working through a diatom bloom in a (relatively) new sand setup and I'm trying ever so hard to be patient. Badger's right, replacing the sand will only prolong the issue. Diatoms take advantage of the nutrients common in new setups, and blooms happen when the beneficial bacteria can't out-compete them. Since a lot of BB live in the substrate, changing it out will just work against building up a good colony.

But even once the bloom is over, you should keep in mind that sand will always look a little dirty. Because detritus can't sink down through it, everything sort of sits on top. You can vacuum it up gently, but you'll never get everything without sucking up a bunch of sand too. It's something you just have to learn to live with. I have an older sand setup where the sand used to be an extremely bright, near-white color, and is now an actually quite lovely sort of light tan. Sand substrates simply aren't the right substrate for clean freaks

 

[Kelly Preussner]

Thank you all. Just changed the water & did a clean. Yes, it all brushed off easily so looks like that is my problem. When vacuuming I mixed up the sand so it definitely looks better & wiped off the leaves & decor. I also got a few nerite and they seem very happy. Tank looks much better now. I will also keep the lights off for a few days. Thanks again