Very high nutrients, no nuisance algae and macros barely growing

[Bars]

This has been an ongoing battle for a year now. I have always had high nutrients (nitrates 20 - 30, phosphates around 0.1) and just let it go. However, both seem to be creeping up significantly.

So about a month ago, I threw one of those plant basket for ponds in my sump, added a 30 gph freshwater pump in there for a bit more flow, got a 6000k LED bulb hanging ~ 4'' above water level and added a hand full of chaeto. The light's on during the hours my DT light's off. So far, the chaeto ball hasn't even doubled in size. It's looking good color wise and not falling apart and I turn it around once or twice a week. My skimmer isn't stripping my tank of nutrients either, because it's working rather poorly.

I've got a few stray strings of caulerpa in the DT that has settled on some live rock. Has been in the tank for months, but is barely growing as well. So slow actually, that I haven't had the need to trim it yet. I have never had any nuisance algae in the tank other than a green film on the glass and some brown stuff on the sand bed for a few weeks.

Any ideas what's going on? Ideally I want my nutrients even below the usual 20 (nitrates) and 0.1 (phosphates) to hopefully improve growth and coloration of my corals a bit, since that has been lacking for months as well.

 

[SMSREEF]

My guess is that it is low elements like iron holding up the growth.
You could do an ICP to check it out for sure, or just order and dose some Chaetogrow which has the elements macros need.

 

[Tamberav]

I dosed a product called CheatoGro when I had a macro tanks. It could be a trace element issue.

 

[Bars]

How quickly can these trace elements be consumed? I did an ICP test about 3 months ago and most of my trace elements were actually on the high side. Since then I've probably done a 20% water change and that's it.

Was about to do another ICP test anyway, so I'll see what needs to be changed

 

[SMSREEF]

How quickly can these trace elements be consumed? I did an ICP test about 3 months ago and most of my trace elements were actually on the high side. Since then I've probably done a 20% water change and that's it.

Was about to do another ICP test anyway, so I'll see what needs to be changed

I do 15% water change every 2 weeks. I dose All for Reef daily (which has trace elements with Alk and Calcium). I dose Chaetogrow about once a week and my iron was to low to measure last ICP test 11/1. Actually Quite a few elements were to low to measure. I think depending on what you have in the tank, you can burn through some trace elements rather quickly.

When my macros are not growing or losing color I make sure I have NO3, PO4 and dose chaetogrow.

 

[Garf]

Sounds like you need a couple of good water changes. Will normalise traces and reduce your nitrate etc.

 

[Crustaceon]

Either low trace elements, especially iron or the light intensity/duration isn’t enough.

 

[Erasmus Crowley]

So about a month ago, I threw one of those plant basket for ponds in my sump, added a 30 gph freshwater pump in there for a bit more flow, got a 6000k LED bulb hanging ~ 4'' above water level and added a hand full of chaeto. The light's on during the hours my DT light's off.

The part about the light jumps out at me. How many watts does this LED bulb consume? It sounds like you went the hardware store light route.

I also decided to use hardware store lights, but I'm currently using 3x 15w 5000k LED bulbs plus an extra supplemental 18" actinic t5 over a single 20 gallon sump. I also painted the inside of my tank stand white just to reflect as much light as possible back into the chaeto. This stuff can consume a LOT of light if it's available, and if you're only using a single 5w or 9w LED bulb, it's going to grow really slowly, or not at all.

 

[Bars]

The part about the light jumps out at me. How many watts does this LED bulb consume? It sounds like you went the hardware store light route.

I also decided to use hardware store lights, but I'm currently using 3x 15w 5000k LED bulbs plus an extra supplemental 18" actinic t5 over a single 20 gallon sump. I also painted the inside of my tank stand white just to reflect as much light as possible back into the chaeto. This stuff can consume a LOT of light if it's available, and if you're only using a single 5w or 9w LED bulb, it's going to grow really slowly, or not at all.

You're right, it's just a simple bulb from my local hardware store. Only 8.5 watts

So it's probably not enough light and possibly a lack of certain trace elements?

 

[laverda]

I find inexpensive red and blue LED grow lights work much better fir growing algaes. Amazon has all sorts of styles.

 

[Erasmus Crowley]

I find inexpensive red and blue LED grow lights work much better fir growing algaes. Amazon has all sorts of styles.

I wish that @Bulk Reef Supply would make a video testing this. White vs red+blue, watt for watt.

I see this "wisdom" shared all the time, but everytime someone in the indoor gardening hobby tests it, the whites win. You can find a whole bunch of videos about it on YouTube if you're curious. Terrestrial plants grown under just red+blue always seem to end up weighing less, and they're usually malformed in some way. Either the leaves are wrinkled weirdly, or they leaves are underdeveloped, or the plant grows really thin and the stalk can't hold up it's own weight, or all of the above. It seems like plants need the other spectrums in white lights for more than just photosynthesis.

I don't know if those results translate to marine macroalgae, but since no one has done the same head-to-head tests in a refugium setup, I just assumed that full spectrum white is healthier than red+blue similiarly to how it is for terrestrial plants. That's why I decided to swap all my red+blue bulbs for full spectrum whites.

 

[Erasmus Crowley]

You're right, it's just a simple bulb from my local hardware store. Only 8.5 watts

So it's probably not enough light and possibly a lack of certain trace elements?

That's my guess exactly. In that order. Maybe aim for something like 30w per cubic foot of chaeto as a minimum and throw in some chaetogro?

Of course, I'm pulling that number out of thin air so take it with appropriate skepticism.

 

[jt8791]

Finnex planted plus worked great for chaeto on my last tank. I know they are heavy on red, can’t remember which one it was, 420 or 440. Want to say it had blues but think they were more of nightlight blues, not very powerful, but it grew macro no problem

 

[Seabiscuit]

That's my guess exactly. In that order. Maybe aim for something like 30w per cubic foot of chaeto as a minimum and throw in some chaetogro?

Of course, I'm pulling that number out of thin air so take it with appropriate skepticism.

I like that estimate.

 

[Seabiscuit]

You're right, it's just a simple bulb from my local hardware store. Only 8.5 watts

So it's probably not enough light and possibly a lack of certain trace elements?

Keep us updated. I'd like to know what you will end up doing and how it will work out.

 

[Bars]

Thanks guys, I'll start looking for a new light
Amazon can't/won't ship lots of stuff to my country unfortunately, so gotta look somewhere else.

 

[Bars]

Keep us updated. I'd like to know what you will end up doing and how it will work out.

Will do On a very tight budget right now, so can't order a bunch of stuff yet. Definitely going to look at different lighting.

 

[Bars]

Oh I just remembered I have a 30 watt led flood light lying around somewhere. However, spectrum is around 4000k I believe. Could the lower spectrum cause problems or would this be sufficient?

 

[Erasmus Crowley]

Oh I just remembered I have a 30 watt led flood light lying around somewhere. However, color temperature is around 4000k. Could the lower color temperature cause problems or would this be sufficient?

I don't think that the macroalgae will care about the color temperature at all.

I'm slightly worried about the center of the beam being too focused. Unless the chaeto is tumbling well, you probably don't want one super bright spot in the middle while the edges are in shadow. I'd suggest that you mount it high up so that the beam spreads out, and then it should be a great light for you.