Achieving Low Phosphates/Nitrates - What am I doing wrong?

[Konydiver]

Hi everyone,

I'm new to posting in the forum but do read a lot of these threads frequently.

My tank has been running for about a year now (Was longer before but did a full breakdown and restart). From the beginning we've had a constant battle with phosphates and nitrates and I'm trying to achieve low ranges to help with my coral health (PO4 < 0.05 and NO3 < 10PPM. Some of the corals are struggling (brown, withdrawn, etc) whilst others appear to be doing ok. I beleive I was starving my corals from nutrition as I didn't fully understand the difference between nutrition/nutrients.
We've tried loads of things but this is what we have at the moment:

• 300l tank
• Clarisea sk5000 Filter roller
• Deltec sc1351 protein skimmer
• Currently running rowaphos (100g) (as phosphate high - don't want this to be a long term solution)
• 45 x 21 cm refugium with chaeto Lit by kessel h80 (set at grow at 100% intensity) at 8inch above water line + tunze refugium light lit underneath the chaeto (Run on reverse schedule - about 16hrs)
• Powerhead within chaeto chamber to create extra flow

Maintenance:

• Make our own RODI water
• Weekly 15% water change, siphoning sand bed

Dose:

• Brightwell aquatics chaetogro 6ml a day
• A- and K+ Elements 3 ml a day each
• Red Sea Alk, Ca, Mg

Food:

• A small cube of homemade "reef chilli" (mysis, krill, brine shimp, silver tail, squid, reef roids, formula one marine pellets) - once a day
• 12ml red sea AB+ a day
• Small amount of nori for the 2 tangs we have

Stock:

• 1 regal tang (fairly large), 1 yellow tang, firefish, 4 wreck fish, 2 clowns, yellow assessor, naoko wrasse.
• Decent amount of Corals including some sps but the tank is not filled as I'm hesitant to add more.

Our phosphates are still at 0.15 after coming down from 0.39 before rowaphos. And nitrates are at about 25, they never move.
Any ideas how to get these down? Feel like we've tried so much. And I thought the refugium would be enough to support the filtration after the mechanical filtration? I heard so many people talking about their refugium thriving and exploding in growth... ours is growing but not at the rate I expected and not using up the nitrates/phosphate (tried harvesting little bits to see if that would help).

Sorry for the long post and if I've done something wrong with posting.

Hope someone can help.

 

[Dennis Cartier]

Welcome to R2R!

Hmm, your nitrates are staying stubbornly high. Getting nitrates down is not particularly difficult, but before we tackle that, we should look into why yours are so high. Finding and addressing the root cause, will help to make the lowering of them easier and possibly not even needed once the source is addressed (possibly).

For your feeding, is much food going uneaten? Do you have a sump and do you turn off the flow through the sump during feeding? How are you testing the nitrate, which test? Is your chaeto growing?

My suggestion is to examine each aspect of your current maintenance routine to look for causes of the nitrate accumulation.

Dennis

 

[Rtaylor]

I know Reef Roids is super high in phosphates. If you are feeding it daily that might be part of the problem. Given you are also dosing AB+, you could get rid of that all together. I assume you’re dosing chaeto grow to encourage it to grow in your refugium, but it is the same as dosing nitrates and phosphate directly into the tank. You want it to consume nutrients from the water, but it’s easier to use the plant food you’re feeding it.

 

[Dennis Cartier]

I know Reef Roids is super high in phosphates. If you are feeding it daily that might be part of the problem. Given you are also dosing AB+, you could get rid of that all together. I assume you’re dosing chaeto grow to encourage it to grow in your refugium, but it is the same as dosing nitrates and phosphate directly into the tank. You want it to consume nutrients from the water, but it’s easier to use the plant food you’re feeding it.

Actually Cheato-Gro does not contain and nitrates or phosphates. It just replaces the elements that get depleted by macro growth. However 6 ml a day strikes me as being a lot to dose if your cheato is not growing already. The iron in it combined with high nitrate and phosphate will brown out your corals for sure.

I agree about Reef Roids being super high in phosphates.

 

[Rtaylor]

Actually Cheato-Gro does not contain and nitrates or phosphates. It just replaces the elements that get depleted by macro growth. However 6 ml a day strikes me as being a lot to dose if your cheato is not growing already. The iron in it combined with high nitrate and phosphate will brown out your corals for sure.

I agree about Reef Roids being super high in phosphates.

Thanks, I guess I just assumed it had those as regular plant food dies. Good to know.

 

[Reef.]

I would definitely take the reef roids out of your frozen food, that is extremely high in PO4 and I would think your corals don’t need feeding daily.

I would try that first as you don’t sound as if you are doing much wrong, your setup sounds good...keep in mind your nutrients are only slightly on the high side, you shouldn’t have to do much get them down, try one thing first, see if it works before trying something else.

Once you remove the roids, you could do a couple of large water changes to get your lvls down and start from there.

 

[Konydiver]

Thanks for your replies.

I do have a sump and turn off the return when feeding and just leave the wave makers on. Most of the food does appear to be eaten, not sure if all.

I use the salifert nitrate test and hanna ulr phosphate checker. With the nitrate test, I tested my salt mix and it came back as 0. I do believe the Chaeto is growing, trying to take progress photos but there are signs of growth and no die back.

In terms of reef roids, I added 2tbsp into the home made food I made. This created like 10 zip lock bags of frozen food so assume its not going to be a lot in each.

The 6ml Chaeto gro is just the elements and is the recommended amount to what they say, I just didn't want to take chances

 

[sarcophytonIndy]

Thanks, I guess I just assumed it had those as regular plant food dies. Good to know.

How well is the chaeto growing? The more growth/harvesting, obviously, the more nutrient export. You may need a stronger grow light, more flow through the chaeto bed. Also, any mechanical filtration, such as socks, if not cleaned regularly, will turn into nitrate factories.

 

[Konydiver]

How well is the chaeto growing? The more growth/harvesting, obviously, the more nutrient export. You may need a stronger grow light, more flow through the chaeto bed. Also, any mechanical filtration, such as socks, if not cleaned regularly, will turn into nitrate factories.

The chaeto is growing, not sure if it's a good amount or not but it is getting bigger. But I have been testing nitrates for weeks and they never seem to move.

I mentioned in my original post, I use a filter roller mat as i got tired of filter socks as well as using a protein skimmer

 

[sarcophytonIndy]

Just to give you some perspective, I have a 125 with a 55 gallon DIY sump underneath. The middle third of the sump is packed with chaeto and ulva. I have to harvest bi-weekly, and when I do, I pull out enough to completely fill/pack a one gallon zip-lock, which I sell for credit at the LFS. I don't use any socks so the chaeto/ulva bed is my mechanical filtration.

 

[Konydiver]

Just to give you some perspective, I have a 125 with a 55 gallon DIY sump underneath. The middle third of the sump is packed with chaeto and ulva. I have to harvest bi-weekly, and when I do, I pull out enough to completely fill/pack a one gallon zip-lock, which I sell for credit at the LFS. I don't use any socks so the chaeto/ulva bed is my mechanical filtration.

That was the point in my post saying I hear everyone talking about how crazy quick it grows yet i thought with the amount of light/nutrients i should be filling my refugium chamber in a matter of weeks. I've started taking progress photos this week, want to see how long it takes to fill it up before harvesting. I was taken chunks of it out before but that didn't seem to dent anything

 

[sarcophytonIndy]

You may need to a stronger light and/or better flow through your sump/fuge. Here is the light I am using

 

[Konydiver]

That's frustrating if that's the reason as using the Kessil H80 on top (which I bought a few weeks ago as read good reviews it was an excellent light) and a Tunze Refugium Light in the water underneath to light both sides (which is what I had originally. I figured both of them would be enough for the size refugium I have.

Plus for flow, I have a powerhead directed straight at the chaeto, would that not be enough?

 

[Konydiver]

My refugium

 

[sarcophytonIndy]

For the flow, it is really how often does your display tank water volume pass through the cheato. Personally, what I would try; I would remove all reactors. It could be that the chaeto is not growing well due to the phosphate reactor removing too much of the phosphate.

 

[Konydiver]

For the flow, it is really how often does your display tank water volume pass through the cheato. Personally, what I would try; I would remove all reactors. It could be that the chaeto is not growing well due to the phosphate reactor removing too much of the phosphate.

I only added the phosphate reactor in the last week as when i tested phosphate it was around 0.39 ppm

I tested a couple days ago and it was 0.15. Don't want to use rowaphos, just having it run as all my filtration doesn't seem to cope with my NO3/PO4

 

[sarcophytonIndy]

If you are not having nuisance algae issues, and your corals look good, I wouldn't worry too much. I run my fuge light on a reverse schedule as well, but mine is 12 hours on 12 hours off. You might try adding another macro algae to the fuge. I have ulva as well as chaeto, and I notice at times one will be thriving more than the other, but then it will reverse. I figure its likely that they have slightly different nutrient requirements/sweet spots, and they are self-regulating.