DOC question

[easyian]

Can you have a DOC breakout? I recently lost all my fish to Marine Velvet about a month ago. So the tank was treated and sat empty save for a few inverts(feather duster, 10 hermits 15 asst snails and a peppermint shrimp). All of which are thriving. My problem is after about two weeks with no fish i noticed an oil slick on the top of the water which I have never experienced since i set it up about 5 months ago. I run a canister w/o a skimmer. I have since done a few water changes and it has cleared the problem about 80%. Is it time for a skimmer? I was planning on drilling for a sump when money was a littler better.

Ian
90 gal w minimal lr
Filstar canister
just added a small saddle back today

 

[fishfreek]

In theory I would say yes you could have a 'breakout' of DOC in the water. How? Well the DOC's will come from the life in the water and the items we put into the water. Stuff like food, top off water, airborn particles all contrubte to the waters quality. Items in the water like bactera, fish waste, decomposing creatures, etc all contribute to the DOC levels aswell.

If you saw the outbreak a few weeks after all the fish was taken out of the tank then my guess would be that the DOC's where really a collection of bactera that had died of due to the lower ammonia production. Think of the bactera population as a population in contant flux. As more ammonia load is generated more bactera reproduce to cope with the additional food source. As the load is lowerd less bactera are produced and the ones that are in excess die off.

This is only a theory so it could be full of DOC aswell.

 

[easyian]

Sounds like a fine theory and i will take it at face value. Thank you for the reply

Ian