WARNING---LONG POST =
A little info about cleanup crews. I see so many video's and pics of people with algae problems, dino's, etc etc. And 95% of the time, there is an extreme lack of clean up crew.
Lots of people think of them as just the critters to eat uneaten food, fish poop, detritus etc etc., BUT they are sooo much more than that.
Think of them as your first line of defense for oh so many issues that hit your tanks. A heavy combination of snails of various species, few crabs, shrimps of various species and different starfish are just the start.
Here is just my thought's and opinions on start up crew for keeping your tank healthy BEFORE something goes wrong.
As soon as your tank is cycled and you add your first fish, add a couple of hardy turbo snails per 25 gallons.
After about 3-4 more weeks, add 2 more turbo snails per 25gallons, but also mix it up, not the same species. Start with Pacific Turbo's or Mexican Turbo's then second batch make them Astrea's. Also at this point in time add about 5-8 nerite snails per 25gallons.
Add 2-4 Emerald crabs per 25 gallons and add 5-10 dwarf blue leg hermit crabs. Get them as small as you can. Remember for every one hermit you add, you need to add 5 empty shell's just slightly larger than the hermit. You can pile them up in back somewhere out of sight. But you need some new shells for them to grow and not eat your snails and each other just for their shells.
Add 3 peppermint shrimp per 25 gallons. Yes at least 3. I see people all the time oooh i got aptasia and throw in one shrimp and get upset when it dont help. They eat more faster when there is competition among themselves. Some die and some just only eat leftover foods. Over all they are amazing adept cleaners for all kinds of leftovers and detritus.
Now your into month 4-6. Now you can add 2-4 nassarious snails per 2sq ft bottom space.
By now you should have 8-10 turbo snails per 50 gallons. 15-20 nerite snails per 50 gallons, and now add some cerith snails. Dont add the ceriths till the tanks is established pretty well. You will need only 3-5 per 25 gallons. If most survive they will reproduce for you in your tank so its a one time purchase. Also at this point add grey, green, tan or light brown colored brittle stars. Put one per 2sq. ft of space. You can also add same or similarly colored serpent stars in the same amounts. I say those lighter colors, cause there are some darker ones that are a little aggressive and most of time the lighter shaded ones are not that species. (most of time)
After your tank has been up and running for 5 or 6 months you will need to maintain your clean up crew. Only keep hermits smaller than half inch, donate or return larger ones to cut down on predation. You should have at least 8-10 turbo snails per 25 gallons. You should have at least 20-30 nerites per 50 gallons and at least 15-25 ceriths to 50 gallons. You can also get dwarf cerith snails that are really tiny and can get in tight spaces, but if you run a smaller sized wave makers skip them as they have a tendency to be attracted to the plastic and get munched or clog ur pump.
Sorry so long but if you made it this far, its time to get a Tigertail Cucumber. They stay on your sand layer, and will literrally consume the sand dirty, and poop it out clean. You can put 1 per every 2sq.ft of aquarium bottom space. The absolute best sand sifter around and will not starve out and die because it doesnt completely devour every living thing in your sand.
Lastly, it is up to you to maintain your clean up crew. That means yes, every month your going to need to buy replacements for those that died, got ate or mysteriously just vanished.
If you stay on top of your clean up crew right from the start, 90% of the algae/bacteria issues most commonly seen will never happen in your tank, as long as you keep your water chemistry in check.
Hope someone gets some help from this. Long winded, and just some food for thought. Many ways to do so much in our tanks, so always ask questions and always go to Just Fish.
BE PROACTIVE--- NOT REACTIVE