Water Change or Dose?

Albertan22 · Mar 15, 2020

So I've had lights on for my new build for 2 weeks now. The tank has some LPS, an RBTA from the tank I took down along with a couple of Acro frags from that tank I salvaged but don't really expect to make it (but still doing ok so far). The tank has dropped 1 dkh in Alk over the last 2 weeks (8.5 down to 7.5) which isn't much. I'd normally deal with that through a water change. The kicker is that I don't have any detectable nitrates or phosphate yet so I'm a bit hesitant to do a water change yet. The tank is fishless as I'm running my fish from the last tank through QT for good measure and fallowing my old rock for a fresh start but I have been feeding the tank every day. The skimmer has been turned off this entire time and I haven't started up the refugium yet (algae is living in a 5 gallon pail).

Should a person just do a water change at this point to reset the big 3 or maybe dose a little and keep letting the nitrate and phosphate build a bit?

Leslie Tabor · Mar 15, 2020

I find it odd if you have been feeding every day for 2 weeks and have an anemone producing waste, that you have zero nitrates/phosphates. What test kit are you using? Do you have a lot of algae?

Albertan22 · Mar 15, 2020

Leslie Tabor said:
I find it odd if you have been feeding every day for 2 weeks and have an anemone producing waste, that you have zero nitrates/phosphates. What test kit are you using? Do you have a lot of algae?

I'm using a salifert kit for Nitrate and a crap fluval kit for phosphate that I don't trust much. I don't have any algae to speak of. I just cleaned the glass for the first time yesterday. The rock was all fully cycled though. Most of it came from my 120g that was up for 10 years and the rest sat curing in a barrel for 4 months and was fed regularly.

Leslie Tabor · Mar 15, 2020

Hmmm....interesting. I am by no means an expert lol so I don't have a great answer. I would do a water change, dosing is not anything I have experience with except a brief experiment in my first year or so...and I killed all my SPS/LPS sooo...

Natescorals · Mar 15, 2020

How big is the tank? I would add some fish and start feeding the fish then you’ll see nitrates and phosphates start to rise. Maybe invest in a Hanna Ultra low range phosphate tester? I don’t know much about the fluval but a lot of phosphate tests are very inaccurate. But double check phosphates. What do you use to test the alkalinity and calcium?

Albertan22 · Mar 15, 2020

Natescorals said:
How big is the tank? I would add some fish and start feeding the fish then you’ll see nitrates and phosphates start to rise. Maybe invest in a Hanna Ultra low range phosphate tester? I don’t know much about the fluval but a lot of phosphate tests are very inaccurate. But double check phosphates. What do you use to test the alkalinity and calcium?

The tank is 180 gallons, total water volume in the system is around 230 gallons. I test alk with a Hanna checker and calcium with a Salifert kit. I've been kicking around the idea of buying a hanna checker for phosphate. It's not something I really bothered to test for before with my old system as it had been stable for around a decade. Now that I'm starting a new system I decided to test for it, but the only thing I could find locally was this Fluval kit which is basically an entry level freshwater type kit that says it's good for marine too.

I won't be adding fish until my rock has been fallow for 45 days. I didn't have any signs of ick in the old tank, but I didn't QT either. I've decided to go the QT route with this system though. I'm going to take the risk on the 45 days instead of 72 days though as my fish from the old 120 gallon aren't too happy living in a 29 gallon QT tank. They've got another 3 weeks before they'll get into the 180g system.