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wanted: tank cleaner


Colossal Squid
Nov 19, 2002
Hey Monty,

I couldn't see in the posting if this was a new tank (ie not cycled at all bar the one week) or if it was an older established tank with a new filter, that would be a different kettle of fish (:biggrin2:) A new tank with such frequent changes will of course never cycle completely and won't be stable enough for cephs. Even in an established tank I subscribe to the "less is more" school of thought unless testing shows otherwise!


We "season" the tanks usually for a minimum of a fortnight, and never wash the sand beds as they come from just outside the door, once a week (ish) we give the sand a wee bit of a stir and siphon off any crud. We keep polychaete worms (maldaniids etc) and some burrowing cucumbers (Paracaudina chilensis) & brittle stars (Amphiura sp) & chitons (Acanthochiton zelandicus) in the sand beds. Any closed tanks (we have a couple) are cycled for 3 months. The problem with traditional water changes is that they inevitably stir things up if done too often and knock off the bacteria (then you have decompsing bacteria in the mix too!) our open system has constantly moving water and although the bacteria does die off etc the waste from that is washed away (we don't have any bioball filters etc, we have sand filters and thats it!!!!!) . In our closed tanks we do a 50% water change once a week in summer and once a fortnight to three weeks in winter (or less...depending on bioload etc).

We can shut down the pumps and work the system as a recirc...officially we have enough reserve water to last 3 days, in reality it would probably last 1 day, then we'd have to release a lot of our stock (this would only be done in an emergency, say an oil spill in the harbour) We run through some 38,000 L every day.

We don't very often do a full "cycle" as the tanks are very rarely left to dry out (the only one I can think of was the octopus tank after an autophagy episode) Many of our tanks have been running for some 77 years!




Colossal Squid
Staff member
Jan 22, 2004
It doesn't sound like this is really a flow through system, but a system that gets lots of water changes. If there is lots of rotting matter (shrimp parts), then just doing water changes many times a week is prolly not sufficient to keep up with decomposition.

Live rock is good for 'filtration' and I wouldn't worry about adding fire worms - the worry is overblown IMO.

Just about any sand bed will stink when you disturb it, so I am not convinced that there was anything bad going on in the sand. Having scrubbed the sand, it is no longer going to function as a 'filter' for quite some time.

The fast fouling of the shrimp water is a good example of how quickly water can foul. To make the water changes work as a primary means of exporting ickies, I would be doing at least 50% daily, and would be more comfortable with 90% daily being careful to not stir up the sand bed.

Also, the water you keep the live food in effects the quality of that food, so I would be keeping the shrimp water clean.

How long have you had the bob's? How much have you been feeding them? What size skimmer are you running?

In my ceph system I have a ton of bristle worms that do a great job of eating uneaten shrimp. So much so that I don't worry about it at all.
Jan 23, 2008
hi, sorry i took so long, i'm new here and didn't realize that there was more than 1 page.:oops: i've had the bobs for about 2 and a half weeks now and the survivors look ok. i am worried about the clean up more than the water quality, since they live pretty close to shore in a tidal area and in pretty nasty conditions. (at least that's where i found them) cleaning the sand is my main concern. we're still looking for scavengers. for now i go in and clean up by hand, which really stresses them out. what should i do when they ink. should i clean it, or let the filter take care of it?


TONMO Supporter
Staff member
Mar 8, 2004
Some people have made nets to clean ink... one suggested method is to stretch panty hose or over some sort of loop. It's often possible to let the skimmer take care of it (which is good, in case they ink when you're not around to notice) but cleaning it is helpful, too. I think the panty hose thing is described in one of the octopus care articles....

I'm not sure what the best strategy is for you... it sounds like you didn't set up biological filtration and get a full cycle, so some combination of water changes and brute-force filtration is all you're using to keep the water clean... this certainly isn't what we recommend, since cephs are known for producing a lot of waste... do you have an undergravel or canister filter as well as the skimmer? In addition to the water changes, you may want to change filter media often.