Healthy, thick cheato but phosphate increasing

BLineDisaster

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Hello all,

My chaeto has been growing awesomely, it’s thick and curly, dark green, and smells tasty. When I trim it back to a small tennis ball size, within 2 weeks it’s on its way to filling the refugium. So it’s safe to say it’s going well, coupled with my weekly 10% WCs it’s getting the iron it needs too.

my phosphate has been slowly increasing though for a few weeks, it was at 0.03ppm, then 0.05ppm then 0.07ppm and now 0.10ppm today.

I thought that the chaeto became limited when it’s filled all the space and growing dense. Is this true? Have my phosphates been climbing because I’ve let the chaeto grow too much?

Logic tells me more chaeto mass means there’s more chaeto to grow into more chaeto! So my phosphate shouldn’t be increasing.

I’ve just harvested 1/3 of the mass and teased it apart so it’s not so dense and I’ll continue to monitor.

I monitor my import and export closely. In the past week I’ve added 63g of phosgard and halved my daily feeding but phosphate continued to rise.

I tested my RO reservoir and this measured 0.01ppm I’m not too concerned as my Hanna checker resolution is 0.01ppm. So it could be at 0ppm, or 0.02ppm.

Interested to hear your thoughts

Edit: I should add my refugium is my sole method of export. I change my filter floss every 3-5 days and use a Tunze pink light 12hrs a night to light the chaeto.
 
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BostonReefer300

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I agree with the above. Also, 0.1ppm PO4 is what a lot of people shoot for. Personally, my tank seems to do best if I keep it between 0.1 and 0.05. I try to not get stressed about it as long as it's usually in that range. If you're not seeing crazy algae growth, then definitely don't worry. If algae is a problem, then you can't really trust your PO4 and NO3 readings because so much is getting sucked up by algae. Actually, with a lot of chaeto, that could be the problem---you can't trust your measurements because your chaeto is sucking out so much. Again, if you don't have an algae problem, then no worries. If you do have a problem, then keep going with your chaeto (maybe keep the light on longer), but feed less if possible. I'd run GFO as a last resort because it can strip PO4 down very fast and precipitate a dino bloom. If you do use GFO, start with a small amount. If your chaeto is still growing like mad, add more GFO. If your chaeto stops growing, add less.
 
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BLineDisaster

BLineDisaster

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I am seeing green hair algae growth.

What I need to know is will I see better phosphate uptake if I keep thinning out the chaeto, or will a larger mass of chaeto use the more phosphate? Provided that it’s removed before the chaeto can decay (which I’ve not experienced yet, the chaeto looks healthy on examination)

The tank has been reduced to 1 cube a day of frozen for quite a while now. I’ve only fed frozen I don’t use any dried foods and I do not feed any particulate foods like reef roids. I do feed reef energy at the recommended daily volume.

Chaeto is currently on a 12hr reverse cycle. I haven’t increased my photo period yet because nitrate is low and as I understand N : P is consumed 1:4.
 

damsels are not mean

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What I need to know is will I see better phosphate uptake if I keep thinning out the chaeto, or will a larger mass of chaeto use the more phosphate? Provided that it’s removed before the chaeto can decay (which I’ve not experienced yet, the chaeto looks healthy on examination)
Trimming it might reveal parts of it dying off? Not sure but if any of it does die that's only adding to phosphates. It could also be nitrate limited.
 

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You're not limited on anything if your chaeto is growing rapidly. The optimal amount of chaeto will have enough mass to support adequate further growth to keep your nutrients at the desired level. Too little and it'll seem to grow fast, but there's not enough initial mass to sop up enough nutrients. Too much and you'll get a giant bush that is blocking light to the bottom of the bush so that only the top layer is engaged in photosynthesis. Then you get die-off underneath that leads to more nutrients. In any case, in my past experience with chaeto, the best results came from 1) having good flow in the refugium that tumbled the chaeto and 2) only harvest chaeto when it got too big to tumble. In this way, I kept almost a steady-state mass of chaeto. Granted, I had to harvest it a couple times a week---but I just did that at the same time I changed filter socks. Using this method, the only variable I would change was the light cycle depending on how my nutrients were doing.
 
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BLineDisaster

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You're not limited on anything if your chaeto is growing rapidly. The optimal amount of chaeto will have enough mass to support adequate further growth to keep your nutrients at the desired level. Too little and it'll seem to grow fast, but there's not enough initial mass to sop up enough nutrients. Too much and you'll get a giant bush that is blocking light to the bottom of the bush so that only the top layer is engaged in photosynthesis. Then you get die-off underneath that leads to more nutrients. In any case, in my past experience with chaeto, the best results came from 1) having good flow in the refugium that tumbled the chaeto and 2) only harvest chaeto when it got too big to tumble. In this way, I kept almost a steady-state mass of chaeto. Granted, I had to harvest it a couple times a week---but I just did that at the same time I changed filter socks. Using this method, the only variable I would change was the light cycle depending on how my nutrients were doing.
It’s not possible to get it tumbling in my sump but I do physically turn it all over every few days so I’ll have to make do with that for now.

It sounds like I’ve just gone past that sweet spot where it was maintaining my phosphates by letting it grow too much and restrict itself.

Thanks
 
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It’s not possible to get it tumbling in my sump but I do physically turn it all over every few days so I’ll have to make do with that for now.

It sounds like I’ve just gone past that sweet spot where it was maintaining my phosphates by letting it grow too much and restrict itself.

Thanks
If you put a small sicce powerhead in there at the bottom, that could possibly work. If you're worried about the chaeto plugging it up, you can put some coarse foam around the intake. Good luck
 
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Ah i see what you mean. Then it's probably just not big enough or well lit enough to keep up. You could try a 24hr cycle? Or if you have the ability to make it brighter that can help too.
Wouldn’t that just make my nitrate even lower? It’s currently around 2ppm. I’ve got a Tunze 8831 over it so I think it’s got plenty of light
 
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If you put a small sicce powerhead in there at the bottom, that could possibly work. If you're worried about the chaeto plugging it up, you can put some coarse foam around the intake. Good luck
That’s a good idea I’ll look in to this
 

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For what it's worth. I have the same problem. Chaeto growing like a weed but have not seen significant impact on my nitrates and phosphate yet. I figure like everything in this hobby it just takes time to find the right balance.
 

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Hello all,

My chaeto has been growing awesomely, it’s thick and curly, dark green, and smells tasty. When I trim it back to a small tennis ball size, within 2 weeks it’s on its way to filling the refugium. So it’s safe to say it’s going well, coupled with my weekly 10% WCs it’s getting the iron it needs too.

my phosphate has been slowly increasing though for a few weeks, it was at 0.03ppm, then 0.05ppm then 0.07ppm and now 0.10ppm today.

I thought that the chaeto became limited when it’s filled all the space and growing dense. Is this true? Have my phosphates been climbing because I’ve let the chaeto grow too much?

Logic tells me more chaeto mass means there’s more chaeto to grow into more chaeto! So my phosphate shouldn’t be increasing.

I’ve just harvested 1/3 of the mass and teased it apart so it’s not so dense and I’ll continue to monitor.

I monitor my import and export closely. In the past week I’ve added 63g of phosgard and halved my daily feeding but phosphate continued to rise.

I tested my RO reservoir and this measured 0.01ppm I’m not too concerned as my Hanna checker resolution is 0.01ppm. So it could be at 0ppm, or 0.02ppm.

Interested to hear your thoughts

Edit: I should add my refugium is my sole method of export. I change my filter floss every 3-5 days and use a Tunze pink light 12hrs a night to light the chaeto.
Phosphate is being imported faster than Chaeto is removing it. The question is whether the rate of PO4 import has increased, say increased feeding or food change, or the Chaeto growth is slowing down. Chaeto growth might slow down because it has filled up the space or trace elements are depleted. Since you feel that import is stable, maybe look into the health of Chaeto.
 
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