Nutrient management in low bioload tank

[razorskiss]

My young 25 gallon invert only tank has no skimmer and currently houses only 2 ricordea and a seeding of pods. I dose a tiny amount of phytoplankton to maintain the pods as a prophylactic CUC but otherwise don't feed the tank. To try to avoid any nasty outbreaks up front I dosed nitrate and phosphate and levels are currently at about 5 ppm nitrate and 0.03 - 0.1 ppm phosphate (salifert kits). My guess is that as I continue to add corals and the pods and phyto accumulate some nutrient production will happen on its own, but in the meantime should I try to nudge them a little higher with dosing or just keep them from dropping any further?

 

[blaxsun]

Any plans to add fish - or just corals and inverts? Your nitrates and phosphates are pretty good - so I'd probably just try to maintain them at these levels.

 

[razorskiss]

No fish, just corals and small inverts!

 

[PatW]

I agree, your levels look pretty good. You will almost certainly need some nutrient export. The simplest and cheapest method would probably be large water changes. All you would need to do is use the same salt mix and match your salinity and temperature to your tank. Getting an RODI system and mixing your own salt water would be really useful for cost, convenience and quality. Also, doing this would go far to maintaining trace elements.

 

[razorskiss]

I agree, your levels look pretty good. You will almost certainly need some nutrient export. The simplest and cheapest method would probably be large water changes. All you would need to do is use the same salt mix and match your salinity and temperature to your tank. Getting an RODI system and mixing your own salt water would be really useful for cost, convenience and quality. Also, doing this would go far to maintaining trace elements.

This is essentially the plan! I have an RODI set up and currently use tropic marin salt. I plan to watch NO3 and PO4 closely to gauge how often I'll need to do water changes and will start tracking alk / cal / mg more closely once I add more corals. Luckily the tank is right by a window above a garden hose that's always shaded so I installed the RODI setup there. Makes it easy to siphon water out and draw RODI straight into a bucket next to the tank to mix salt in. The tank is acrylic with a lid so evaporation is almost negligible. After a week with no top off salinity went up 0.1 ppt.