Dirt in my tank

[Allen Jiang]

How come there is dirt in my tank which is brown? Is it from the river rock that I put in (had dirt on it) or has it grown there?

[Eric Warwick]

The dirt won't hurt anything in the system--just keep the nitrates under control. Also, it could be algae, so watch the O2 levels.

[Allen Jiang]

how do you monitor the 02 levels?

[TCLynx]

Did you rinse your river rock before putting it in the system? 

Is the "dirt" like sand on the bottom of the fish tank or is it more like really light weight almost floating sludge?

a little bit of sand from the gravel probably won't hurt anything as long as it's just a small amount (like not completely covering the bottom of the tank and not deep enough to create any anaerobic layers.)

If it is more like the light weight sludge it could be fish waste or uneaten feed if you already have fish or like Eric says, it might also be algae or dieing algae.  If it is any of those things, you want to get it pump out of the fish tank and into the grow beds so it can break down in the right environment to feed the plants best and impact the fish least.

As far as monitoring O2 levels, most people don't bother with test kits or meters for it on a backyard scale as long as you don't have too many fish.  You can check at dawn and if you fish are gasping at the surface of the water, then you need more aeration as your O2 level is too low for the fish to comfortably get through the night.  I also noticed that in a heavily stocked system when the water was really warm in the summer I needed more aeration or the fish would quit eating their food since warmer water doesn't hold as much dissolved oxygen and it was more quickly depleted which put the fish off their dinner.

[Allen Jiang]

ok thanks it's kinda like at the bottom of the tank like dirt.

[Allen Jiang]

but the water is clear so is that a good indicator the water is good for fish?

[TCLynx]

Fish usually don't care about a bit of dirt.

Knowing if the water is good for fish, well,

is the water safe to drink?

is there any chlorine or chloramine to worry about or has that been taken care of?

What do your water tests say.  Having a freshwater master test kit and knowing what your baseline water tests say before adding fish can be a good idea to help you diagnose problems if they do happen later.  Also having the test kit to help you know where you are in the cycling process is good too.

[Allen Jiang]

i haven't tested the water because I don't have a test kit for it.

There's no chlorine as i haven't put any in.

And I only got a water tester for pH and some other things

[TCLynx]

I highly recommend getting a test kit or tests to allow you to track

pH (which you have) But you want to be able to check a range of at least 6.0-8.5

Ammonia

Nitrite

Nitrate

and a thermometer is a good idea.

If you say there is no chlorine because you didn't put any in, I guess that means you are using well water.

[Allen Jiang]

I am using tap water which may have chlorine in i and I might be getting a thermometer for my tank. Also how do u maintain your tank if your away on holidays because my tank usually dies up if its too hot.

[TCLynx]

I have top up valves installed in my systems but the smallest tank I have running outdoors now is 300 gallons so the temperature doesn't cook the fish.

[Allen Jiang]

i meant to say dries up!

[Allen Jiang]

my tank is about 50 Litres so yeah what fish can i put in it?