Phosphate Management in Nano Reef Tank

[Zorak]

Hello and happy weekend. I've had a reef tank, or have been trying to successfully get one up and running for a year now. It has been in operation in that time but it had a little good and an extended bad period. I'll give a history but then I'd like to get to solving the current problem because I think I'm getting close to where i can be successful.

History: About a year ago I purchased a Fluval Evo 13.5 from my LFS, purple dry rock, a couple 5 gallon batches of seawater and set up my tank. I waited for a couple of weeks until the tank tested 0 ammonia and got my first clownfish. I measured nitrates using the same kit as for my freshwater setups (API) and I had a short period of what looked like diatoms / brown algae and then it paused. I thought that meant I could start getting coral, particular because everything I watched on YouTube they were able to start coral almost immediately. Over the next couple of months I spent several hundred dollars on soft and LPS corals from my LFS. I'd bounce the idea off of them and they greenlighted so I kept going. I would do the dip on corals that eliminated pests before putting them in my tank. Green hair algae started to show up and I would clean it every couple weeks as best I could before bubble algae started to show up and overran not only the green hair algae but it also started to smother and kill my corals. During this time I had also added peppermint shrimp from Algaebarn (bought copepods at that time) and a brittle starfish from my LFS to my tank without issue. My cleanup crew was a conch and some trochus snails. As bubble algae could not be managed by any of my cuc (and emeralds are apparently hit or miss) I read online and was advised by my LFS (off the record) to try Vibrant. When I added the correct dose of Vibrant for my tank size it did not kill the bubble algae but it did kill my starfish, my cleanup crew, and all my remaining coral that prior to that one dose were all doing fine. Only my clownfish survived. I did a big water change in the midst of this, disposed of all the coral plugs and empty shells and turned the lights out. This was probably at the 6-8 month mark. I don't blame Vibrant as a product, maybe what I got was a spoiled or bad one, I don't know. I do know i don't want to add any more unnecessary chemicals to my tank. Frankly, had I lost my clownfish I'd have fully quit the hobby. Taking care of her was all that was keeping me in it. With the lights out all of the algae has died and I have essentially a "clean" tank. It has sat in this state for a few months. I have a little bit of coraline algae in my tank but it's nothing like i would have expected to see grow.

Present: I've added 6 blue leg hermit crabs, 3 nassarius snails, and 4 astrea snails (1 that lives on the glass, the other 3 murdered by the crabs within the first two weeks). Unfortunately my LFS does not sell trochus snails and online order minimums aren't low enough for someone with a nano tank cuc need. I also purchased a clownfish friend for Dot, my first one, that has thankfully survived. I got him from Algaebarn. I feed my tank frozen only once a day alternating between mysis and brine shrimp. About 1/3- 1/4 of a cube.
I change water weekly about 1-1.5 gallons and make water from my BRS ro/di system and instant ocean reef crystals. I have had a salinity checker and just recently bought nitrate and phosphate Hanna checkers, no more games or guessing. I went 3 weeks without a water change this past time as I was researching filtration changes and was making my decision as well as waiting on the Hanna checkers, we'll get back to those values shortly. I bought filter floss, which I put in chamber 1 and have 0.8 rox activated carbon from BRS and micro mesh media bags which would go into chamber 1 but haven't installed yet. Not sure I need it, which I'll get to. I've been running the stock light for 3 hours the past several weeks - 1 hour white, 2 hours blue - no algae yet. My media trays are 3d printed chamber 1 and 2 I got from Etsy some time ago that also came with random flow nozzles for my pump outflow. I upgraded my stock pump previously to a Sicce 0.5. I am only currently using chamber 1 with the floss which just went in with this recent water change (all of the filter media upgrades arrived last night).

Questions: Before my water change last night my nitrates were at 45 and phosphate at 0.9. I did a 2 gallon water change and rechecked. Nitrate went down to 15.6 and phosphate at 0.7. So replacing my old filter media (rinsed in water change bucket but several weeks spent in tank) and the water change seemed to have made a significant impact on the nitrate and dropped the phosphate by the same percentage as the water change. I will be swapping the floss every 3 or so days moving forward.
1.) Based on these values I think my nitrates are in a good place for softie corals. Phosphate still seems high, how should I manage it?
2.) I've already bought the IM chaeto max light to use my chamber 2 as a refugium which I'm prepared to do. Is that the best solution compared to GFO, purigen, chemipure, or a protein skimmer?
3.) I keep reading on these forums and elsewhere but nothing close enough to my scenario to make the final decision. GFO sounds like it could do more harm than good to my small tank. Purigen doesn't seem to directly address phosphate, and chemipure seems to be GFO carbon. Would these all just end up crashing my phosphate and put me in another bad scenario?
4.) How do I know I can increase my light or what do I gauge off of to know its ok to get back to "normal lighting"? Perhaps my tank has aged enough that algae won't be a problem but to say I'm gun shy is an overstatement.
5.) What values do I need to get to before I can get some softies and a couple rock flower anemones?
6.) I don't notice my water as unclear or yellow. Is there any reason I should add the 0.8 rox carbon now or just wait til I can get my toadstool and other soft corals to mitigate chemical warfare?

Thanks and best regards.

 

[Mr. Mojo Rising]

Nitrate is reduced by the percentage of water change, so a 30% water change will reduce nitrate by 30%, 50% by 50% and so on...

Vibrant is an algaecide, it kills all algae, but corals have algae in their flesh, so the vibrant also kills the algae the corals need to survive. Don't use this in a reef tank

It sounds like phosphate is leaching from the rocks, so IMO a type of gfo is best to drain it out. You can put some in a small baggie and put it in your system somewhere.

I would turn the lights up. Don't be afraid of algae, its not only lights that cause algae, it takes a few other ingredients.

Add some activated carbon in a bag to help with yellow water.

Hopefully you're doing weekly water changes, which is the best maintenance you can provide to a tank that size. I do about 20% weekly on tanks.

 

[Zorak]

Nitrate is reduced by the percentage of water change, so a 30% water change will reduce nitrate by 30%, 50% by 50% and so on...

Vibrant is an algaecide, it kills all algae, but corals have algae in their flesh, so the vibrant also kills the algae the corals need to survive. Don't use this in a reef tank

It sounds like phosphate is leaching from the rocks, so IMO a type of gfo is best to drain it out. You can put some in a small baggie and put it in your system somewhere.

I would turn the lights up. Don't be afraid of algae, its not only lights that cause algae, it takes a few other ingredients.

Add some activated carbon in a bag to help with yellow water.

Hopefully you're doing weekly water changes, which is the best maintenance you can provide to a tank that size. I do about 20% weekly on tanks.

Thank you for taking the time to read my long OP.

Should I just start the GFO then at like 1/3 of the recommended dose by water volume to avoid crashing my phosphates?

I dont currently have yellow water, it looks pretty clear to me. Is there any other value in running it before I get corals (like toadstool) that may release toxins?

Should I spend some time tapering the lights up or just go back to normal? Once I get to normal lighting does that mean I'm ready to start stocking soft corals?



Side question, not related. I read on these forums something about open top tanks for better oxygen or gas conversion for nutrients management. My Evo has a lid that I've used out of concern that salt would get on my walls and accelerate evaporation.. should I be looking to go open top for the health of the tank (especially as I add corals) or if it ain't broke, don't fix it?

Thanks again.

 

[Mr. Mojo Rising]

I normally start at half the recommended dosage so if you want to start with a third no problem.

Activated carbon also absorbs dissolved organics, but if you have no algae then to me it indicates you don’t have any excess organics. Some people run it all the time some people never and some people sometimes. Try experimenting and see what works for your system, every system is different and actions react differently

If you have the stock light then to be honest it’s not very powerful so you can put it back to normal.

All my tanks are open tops and have been for very long time. I like it. Lots of people suggest lids to prevent jumping fish. Depending on the type of lid , air tight glass lid vs mesh lid will have different affect on the tank.

Oxygenation is very important in salt tanks, the best way to do this is with a skimmer. If no skimmer then you’ll need to point a powerhead or your return towards the surface to agitate the surface. Flat surface is bad.

Salt on the walls means splashing and honestly that shouldn’t happen. There really shouldn’t be salt creep outside the tank. The only exception is with an airstone and most of us would suggest against the airstone for that reason.

Hope this helps. Please post a pic of the tank when you’ve got it set up. Or start a build thread for others to follow. Good luck.