Foam and Film

[PaulPerger]

I am in the process of Curing my rock for my first SW Reef Aquarium. I did a bleach bath for two weeks, then a two week long "rinse" changing water daily until the water showed no chlorine at all. I then transferred the rock to an old 55 Gallon tank where I am curing the rock. I have been running fresh water currently with a pump circulating water from one end of the tank to the other, so there is a good flow of water through the rock. I have been checking Phosphate weekly and then performing a 100% water change. Immediately after a water change the phosphate reading is about 0.75, after one week of water flow, it is reading about 1.5 - 1.7 currently. Week one it was around 2.0. So, phosphates are coming down.

This morning I noticed a film and some foam on my water's surface which I have not seen before. It's been about four weeks now and all of a sudden I am now getting this film (which didn't photograph well) and foam. I don't remember hearing that this is a normal occurrence while curing rock... Can anyone tell me what this might be? Should I be concerned about it? Should I do anything differently?

 

[rayn]

It could just be surface oils if the bacteria is active. Normal overflow takes care of it and we don’t notice it, but no overflow it has no where to go.

Check all your levels...ammonia, nitrite, and nitrate, not just phosphate.

 

[PaulPerger]

It could just be surface oils if the bacteria is active. Normal overflow takes care of it and we don’t notice it, but no overflow it has no where to go.

Check all your levels...ammonia, nitrite, and nitrate, not just phosphate.

I will check them all this afternoon... I didn't think about that possibility as I have never seen that happen before without some source of Ammonia, though maybe there is some Ammonia which would certainly kick start the cycle process and bacteria growth. I'll report back this evening.

 

[rayn]

There is always the possibility of something still being in there, already dead. As it does it’s thing decomposing it will put off the ammonia and kick start a cycle. Whether it is enough to cycle your rock or not, I can’t say. But it is a possibility.

 

[PaulPerger]

I thought I had done a good job of cleaning off any dead bits, but there could be something deep in the rock that I was unable to remove that is finally decaying.

 

[PaulPerger]

Well, well @rayn it looks like you were right...

Ammonia was over 10 ppm!!
Nitrite = 0
Nitrate = 10 ppm
Phosphate = 1.9

So, I drained 95% of the water, and refilled today. I have been doing 100% water changes on Sundays, so I did it one day early this week. Just for my own information I tested by filtered water (Not using RODI yet, that will begin soon as I just bought the RODI unit, but it is sediment filtered and carbon filtered twice) and found Ammonia = 1 ppm, Nitrite = 0, Nitrate = trace, Phosphate = .70.

I am going to test the tank water again daily this week and see how quickly that Ammonia is rising. The water is cold, not heated, so I doubt I am going to get any bacteria growth which is also somewhat evidenced by Ammonia being so high with zero Nitrites.

 

[rayn]

The di will take anything else out of your water and give you a tds if 0. Sounds like you are on track tho

Cold water will have bacteria, just a smaller amount and possibly slightly different strains. It also seems to take longer to cycle. Cold water aquariums run on be same principal.

When you do add heat you will want to monitor again either way to make sure you don’t spike on something.

 

[PaulPerger]

I would venture to say I have something decomposing deep within my rock... Ammonia is rising at a rate of about 1 ppm per day.

Now I have a new question... Previously when cycling a tank (remember my experience is only with Fresh Water tanks) I didn't have the "Rock Curing" step.

As such, I would dose my tank up to ~4 ppm ammonia to cycle it. Considering this rock is producing its own ammonia, should I continue to do 100% water changes every week and wait for the ammonia to drop to zero (I'm guessing this would indicate fully cured rock)?

Or would it be OK to just move on to the next phase, scape the rock, move to SW and let it continue on its merry way to cycling? Either way at this point, I will not add any ammonia until the rock stops creating its own, which I would hope would be an indicator that whatever was decomposing was completely decomposed and then I would insure a full cycle (i.e. 4ppm to zero every 24 hrs for a week with zero nitrites and nitrates).

Again, either way, at this point I am not going to move forward until after the New Year, as there is a Christmas Tree where this tank is going to be.

 

[PaulPerger]

And now my rock appears to be cycling... Ammonia, which has been in excess of 8ppm by the end of each week was only 1.5ppm after a week, but Nitrites, which were zero are now at 5ppm, and Nitrates are at 80+.