Bugs in my freshwater tank

Question
Hi Karen,
I just cleaned my tank and noticed I was picking up (very)small bugs,like the size of sand. They are almost clear and oval shaped and were in the rocks. I noticed them swimming around in the siphon.  I have had my tank for years and think they have been there for a few months at least. I went to my local fish store and they didn't know what they were but thought they weren't a problem. I didn't feel confident in there knowledge. I went to another fish store that thought they were fish lice, but I looked it up on the internet and did not think that was correct. I could be wrong but was wondering if I could get any other answers. I just added salt to my freshwater tank it is 75 gallons, but I have a lot of wood and other stuff in the tank so I put 1/2 cup in. I thought this might help the problem but am not sure. I have never put salt in before and was told 1tbl spoon for every 5 gallons then do a water change in a week. My tank has 6 Cichlids, 2 algae eaters, 1 large gold fish and 3 snails. Thanks for your time.
Jason

Answer
Hi Jason,
Sounds like you have Copepodes which frequently are found in aquariums that haven't been maintained or gravel vacuumed frequently enough or those that have excess nutrients due to a lot of feeding or fish that put a big bioload on that tank. Fortunately these little critters won't harm your fish but they can be a sign that you might should be cleaning your tank a little more frequently. A thorough gravel-vacumming, perhaps everyday for a few days should eliminate the problem. The critters are likely there due to the heavy-eaters you have (the cichlids, goldies, snails and algae eaters) I doubt salt would do much for the copepodes. Of course I can't exactly say they are copepodes but I'm certain they are a species of the many kinds of scavenging organisms that occur in aquariums and all of them are harmless with a simple remedy of a more thorough/frequent tank cleaning.

I really hope this helps!!
Happy fishkeeping,
Karen~