Too Early to Dose Carbon

TechnicalFisher · Apr 19, 2017

Randy- I have an almost 5 month-old 50g cube that I intend to be a mostly sps reef tank. Fishload is 1 small clownfish pair and 2 flasher wrasses. I dose BRS kalk via my ATO using an osmolator with the kalk dispenser and RODI water that shows 0 on the TDM. I also dose NOPOX, which I started about 2 months ago, using .75ml per day. Nitrate is 1ppm and phosphate isn't detectable (but I'm still using a high test so I guess that just means it's less than .1, have ordered the Red Sea low phosphate kit). Calcium ranges between 450-475, Alk is fairly consistent at 10 dKh and PH ranges from 8.1-8.25 through the day/night. Salinity crept a bit high (1.028) until a week or so ago as I was using a hydrometer but is now stable at 1.026, confirmed by a newly purchased refractometer.
I placed a few small starter frags in the tank a month or so ago and, after doing well for a little while, they lost color. Around that time, my nitrates had dropped to 0. I ignored the low nitrates and reacted by assuming my lighting was too intense and lowered the levels. That made things worse and I lost a almost all of a birdsnest frag and most of a superman monti. A hammer coral that had been showing good growth and tissue expansion began receding back up the skeleton. I've gradually increased lighting, while also cutting my NOPOX dose to maintain nitrates around 1ppm and the corals are looking happier, though still pale. Even the superman, which was essentially gone, is starting to show polyps again.

My question, after all of that background, is whether I should even be messing with carbon dosing on a relatively new tank. My thought in doing so was that I'd get off to a good start by limiting algae and starting a program that I'd stick with. However, I'm starting to second guess that theory. Thanks very much for any insight you can lend.

saltyfilmfolks · Apr 19, 2017

I have had a much easier time running a lower alk and slightly higher nutrints. I can use a lot more light that way too.
Were I do carbon dose Id choose vinegar and go with much lower doses. it does help bacteria etc etc, but it also feeds stuff because it is a carbon source.

Oddly I have always had better nutrient reduction just using the coral nutrient uptake(under higher light they eat more it seems,) and a refugium.

edit, And your runing GFO. so it seems to me you are reducing and feeding at the same time.

cjd · Apr 19, 2017

In my experience , salinity creeping up that high could cause a lot of those issues . My birdnest hated high salinity when I would let it get out of range from dosing ALK/CAL . Question would be how long was that salinity that high ? I personally wouldn't do anything different until things recovered . Steady salinity , keeping nutrients at levels you had before and see what happens. This is where aquarist run into problems , we want to change to many things at once not knowing what change was good or what change was bad. I wouldn't say your tank is to young to start dosing carbon , if you wanted you could do it from day one. I say your tank is unhappy at the moment to add anything new to the system.

Randy Holmes-Farley · Apr 19, 2017

IMO, it is a fine plan to dose carbon from the start, as long as you keep track that you do not reduce nutrients too far.

TechnicalFisher · Apr 20, 2017

Thanks everyone for the responses! Nitrates were back down to .25 when I tested last night so I've halved my dose of NOPOX yet again (to .4ml) and may further reduce it.

Thanks @Randy Holmes-Farley clearly I need to to a better job of managing the dose/nitrate levels. Also need to wrap my head around whether I'm going to be committed to the effort of dosing for the long haul. We like to travel a bit and I haven't really thought through what I'm going to do to deal with that. Have debated putting the NOPOX on a dosing pump but scared about what happens if (or more probably when) there is a malfunction. I've finally gotten a good fishroom with RODI and a water-making station so frequent small water changes are pretty easy now. Maybe that's the way for me to go. Out of curiosity, were I to decide to discontinue dosing the NOPOX for the time being, does that need to occur gradually and if so over what time period? Figuring that simply stopping cold turkey would result in a rapid bacterial dieoff.

@cjd, salinity was probably that high for 2 weeks or so. When I was using the Hydometer, it was actually reading a bit low (which given the error was probably right on) until a few weeks ago. After getting it to 1.026 on the Hydrometer I finally got my refactometer, which showed me at 1.028 late last week. Rechecked it last night and I'm actually still a litte high (1.027 ) so continuing to gradually bring it down.

Thanks again for the info.