[webbster45]

i have like purple bubbles and slime growing on some of my rock, what could it be?

[charlie]

Sounds alot like cyanobacteria. Can you siphon it out during a water change?
To find the cause, we need to know about your system.

[webbster45]

well i have 2 maroon clowns i hippo an a jawfish, 20 lbs of live rock but i am am curing 50 right now which i will add in 2 weeks, a 1 inch deep mixed sand bed and crushed coral in a 75 with a cpr sump. my ph is 8.3, nitrate 20 nitrite0 ammonia 0, sp gravity 1.020, alk 300 and im about to do a weekly water change about 10 gallons

[returnofsid]

The Nitrates are probably a lot of your problem. Also not having enough live rock in the tank yet. Crushed Coral is also debatabely a cause. When you say Alk of 300, how are you measuring that? You should have a reading of somewhere around 3.0 meq/l or 7-10 dkH. I'd do larger water changes and siphon as much of it out as possible. A couple more questions...Are you using RO/DI water? How much flow do you have? Is the Cyano growing in a particular area or everywhere? If it's in a particular area, try directing more flow into that area. If it's everywhere, try adding more overall flow to the tank. Do you have any Macro algae in your sump? If possible, stock it up with lots of Chaeto. That will help reduce your high Nitrate levels. Water changes will also help with that. Do larger water changes and maybe even do them a bit more often until you get your Nitrates to 0. Are you running a skimmer? If you plan to add corals or inverts in the future, you'll probably want to slowly raise your sp. gravity to 1.023-1.025.

[webbster45]

3/4 of my bed is sand there is very little crushed coral, my waterflow is about 1700 gps, there are a few random patches of the growth, im using tap water no ro/di unit and i amn doing a 15 % water change and il make sure i siphon it all out, and there is about a handful of macroalgae in the sump...should i get more and yes i am running a skimmer

[Ninong]

Originally Posted by returnofsid

When you say Alk of 300, how are you measuring that? You should have a reading of somewhere around 3.0 meq/l or 7-10 dkH.

An alkalinity reading of 300 ppm CaCO3 is the same as 6 dKH or 2.14 mEq/L.

["D"]

Does anyone know what this maroon algae is? It is over taking my tank. When I pull it of the rocks it comes off in clumps. It compresses when squeezed and for the most part returns to it original shape when let go. If you crush it in you fingers it will break apart.