What’s Growing On My Dry Rock?

[Amaleec]

Hello! Recently I noticed some grey stuff growing on my dry rock, literally overnight. I don’t know if it’s normal or something to worry about. Pics included.

More Info: 

There’s a lot going on in my 20 gallon tank. I started my tank in October, and it finished cycling around mid-November. Currently it is stocked with a neon blue goby, a lawnmower blenny, and a wrasse. I’m fighting back some white sludge that developed from air fresheners being used in the house. I’m using the Dr. Tims recommended products (Refresh and Waste Away). I had a small ammonia spike - but it’s gone now. Testing with the API Saltwater Kit - Ammonia is 0, Nitrate is 0 and Nitrite is 0. I noticed red stuff growing on a diff part of the rock, but I assume it’s Cyanobacteria.

[A.m.P]

Snail droppings

[Tired]

Yeah, that red stuff is cyanobacteria. Let it alone, it'll fade itself back out. 

 

You want more than 0 nitrates. Algae and coral need those to grow, which is probably why your rock is still so very white. I suspect you're underfeeding, since you don't have much in there that would use it up.

[Amaleec]

I have a sponge as part of my filtration and I read somewhere that sponges can be “nutrient traps” should I take them out?

On 12/25/2019 at 5:54 PM, Tired said:

Yeah, that red stuff is cyanobacteria. Let it alone, it'll fade itself back out.

 

[Amaleec]

What measures can I take to raise Nitrates without screwing up ammonia and nitrite? 

On 12/25/2019 at 5:54 PM, Tired said:

You want more than 0 nitrates. Algae and coral need those to grow, which is probably why your rock is still so very white. I suspect you're underfeeding, since you don't have much in there that would use it up.

And should I be concerned about the other green algae growing in here? 🤔

[Tired]

Feed more. If your tank is cycled, it can easily handle a gradual increase in food amount- the bacteria will multiply to handle the ammonia and nitrites easily, you shouldn't have a spike. 

 

No, you don't generally need to worry about algae. You'll have surges of varying types of algae as the rock colonizes, but that's fine. Surges of things happen, then everything reaches a balance. Once you have multiple types of algae and bacteria and all the fun little encrusting things all over the rock, it'll outcompete each other. If you have a good dozen types of algae (which is part of what live rock is great for, that biodiversity), none of them can multiply out of control and cause pest problems because all the rest take up space. That's how you avoid hair algae and bubble algae and diatoms and all those things that people have trouble with. You let them come when they happen, and you keep feeding so that your algae and corals have nutrients, and everything balances itself out. 

 

If you have a big surge of a pest algae (hair algae or something else that tries to grow over your corals, not just algae in general), add more things that eat it and remove some by hand. Continue to feed so that you have nitrates at all times, and it'll fade out gradually as other things eat it and compete with it.

[Amaleec]

Awesome! Thanks!

[paulsz]

Are you testing for phosphates? You will want to test for it if you're not. You will hear people say you want no nitrates and phosphates because it'll cause algae. But you will not want them to be at 0 because that could cause more issues, especially with dry rock. 

 

I would say aim for 5-10 ppm nitrates and 0.03-0.05 phosphates. Maybe even 0.1 ppm phosphates. 

 

[Amaleec]

I tested for phosphates recently after reading this post and they’re about 5.0! 😟I’m going to retest tomorrow but that doesn’t sound ideal.. 

 

With that being said, my corals look happy. My Hollywood Stunner has its tentacles out, my frogspawn isn’t hiding in its skeleton, my zoanthids are actually growing new heads, mushrooms had little babies, and my GSP has extended all of its polyps. The only one who’s unhappy is my Xenia, it doesn’t pulse anymore. I saw this could be an indicator of low pH and sure enough my pH wasn’t even showing up on the scale 😳 I started adding Kalkwasser and it’s better, I tested two days ago and it was at 7.6
 

Other than the addition of Kalkwasser I also started to add more food while feeding to raise nitrates. My ammonia has gone up slightly, but the bacteria seems to be doing it’s job. I’ll test for everything again tomorrow, and hope for the best.

[A.m.P]

Ammonia is usually not a great sign and just about any concentration is harmful to fish and inverts, however if you're using API test kits they're known to false-positive. In terms of the phosphate test - if that's a Hannah checker than 5 may not be equal to "5" - otherwise API kits are not known for doing a great job with phosphates past either "present" or "not".

[Amaleec]

I am using an API kit, and the results I’ve gotten are the following:

pH 7.6

Ammonia .25

Nitrate 5.0

Phosphate 4.0

 

Idk if they’re false positives or not, and my lfs is like 45 mins away.. I should probably just do a water change, right?

 

As of rn, my biggest issue is my cyano. My Hollywood Stunner looked a little unhappy today, but I fed it in hopes it’ll be better.

[A.m.P]

5 Nitrate is fine, if not a little low, I do not know how you would read 4 Phosphate, 0.04-0.4 sure but it's pretty unlikely you're at (4). The ammonia is almost certainly a bad reading, however if you have your doubts there's little harm in  doing a waterchange.

[Tired]

If all your corals look unhappy, the ammonia is real. If all your corals (or even some of them) look fine, you don't have ammonia or nitrites. Corals hate those and will let you know about them.