How much algae should a healthy tank have?

[dtruitt]

Hi all.

Our tank has been up and running a couple of months now. I thought we were through the "uglies," but lately we are seeing some brownish / greenish film or slime (I think film is more accurate) building up on the glass. The substrate is looking a little grimey due to a deficiency in CUC that was addressed yesterday with the addition of 6 more nassarius snails.

I couldn't find a good thread addressing how much algae a normal, healthy tank should have. Where would you draw the line between normal aquarium algae, and a real problem starting?

I've been stirring the sand a bit and using the magfloat every other day or so. This seems to keep things at a manageable level, but I want to make sure I take more aggressive measures if using the magfloat more than once a week is indicative of a problem, for example.

 

[fcmatt]

Worry about algae issues at the 2 year mark. For now just be patient. In a nutshell that is my humble opinion. Keep good flow, skim correctly, dont over feed too much, and clean your glass. A 10% water change every 10 to 15 days or so depending on the tank size. Coralline algae should be growing on the glass on a regular basis as well as the tank matures. A good small healthy cleanup crew is better then too much. Clean your pumps regularly early on and watch how things improve every few months until you hit about 2 years old.

If your tank is less then a year old algae can run wild. No way to explain it. The ugly stages. Dont go crazy chasing it. Dont dump in odd products. Blow off rocks if you want with a filter sock active then remove it a day later to clean it. Stir sand a bit. Keep sump somewhat clean by sucking out debris during a water change. Run a tiny bit of gfo and carbon. About it. Keep it simple.

 

[Flippers4pups]

In all my years reefing I can say that a mature system (year or more) with good consistent husbandry, clean source water, correct water parameters, correct light spectrum and intensity will have a little algae. Mostly film algae, not hair or other nuisance algae.

 

[dtruitt]

Worry about algae issues at the 2 year mark. For now just be patient. In a nutshell that is my humble opinion. Keep good flow, skim correctly, dont over feed too much, and clean your glass. A 10% water change every 10 to 15 days or so depending on the tank size. Coralline algae should be growing on the glass on a regular basis as well as the tank matures. A good small healthy cleanup crew is better then too much. Clean your pumps regularly early on and watch how things improve every few months until you hit about 2 years old.

If your tank is less then a year old algae can run wild. No way to explain it. The ugly stages. Dont go crazy chasing it. Dont dump in odd products. Blow off rocks if you want with a filter sock active then remove it a day later to clean it. Stir sand a bit. Keep sump somewhat clean by sucking out debris during a water change. Run a tiny bit of gfo and carbon. About it. Keep it simple.

The tank is fairly heavily stocked with 66% LPS, 33% SPS, and 10 fish by the end of the week when two more arrive at the LFS. Maybe a better question would be when a little algae in the tank endangers the inhabitants. Everything seems healthy, but I would like to have some rule of thumb to quantify "a little algae" vs. "Coral threatening levels of algae."

In short, we didnt wait as long as maybe we should have to add tougher corals, so I need to keep things in check a little more than if we waited six months to add coral like everyone suggested.

I dont ever intend to put any products in the tank that claim to eliminate pests. The MO with this system is to keep things natural. Add critters slowly and deliberately to eat nuisance algae and invasive invertebrates, run chaeto to manage nutrients.

If algae is getting dangerous, the plan is to run chaeto more frequently, add more / different snails, and think about introducing snails in places where debris may be settling. I recently tossed a turbo and a nassarius in the overflow box, since food was settling in there.

 

[fcmatt]

Just how big is this tank? Is this your 65g?

You have a heck of a lot going into such a small system in a short amount of time if I am guessing things correctly.

I have a total of 4 fish in approx 80 gallon of water and frankly I would maybe add 3 more small ones tops some day. Not 10 or more. And then all that coral? Woooo u r pushing things quick!

 

[dtruitt]

Just how big is this tank? Is this your 65g?

You have a heck of a lot going into such a small system in a short amount of time if I am guessing things correctly.

I have a total of 4 fish in approx 80 gallon of water and frankly I would maybe add 3 more small ones tops some day. Not 10 or more. And then all that coral? Woooo u r pushing things quick!

Yessir. We are sticking with generally smaller community fish (clowns, gobies, a dragonet) give or take a yellow Tang that will find a new home once he reaches 4" in length. Everybody seems happy, and theres enough hiding places that we only see 2 or 3 fish unless it's feeding time.

Water parameters have been stable, and nitrate and phosphate have been so low between the skimmer and chaeto that we kind of need more fish to ensure the zoox have enough nutrient.

We were planning on taking things slow, but all of the coral has looked so healthy that it's hard to justify waiting beyond "just in case." We had a platygyra bite the dust, but the turbo snails seemed to have a vendetta against that frag unlike any other.

So now I'm paranoid about every little "problem," even when everything looks healthy.

 

[MaccaPopEye]

Yessir. We are sticking with generally smaller community fish (clowns, gobies, a dragonet) give or take a yellow Tang that will find a new home once he reaches 4" in length. Everybody seems happy, and theres enough hiding places that we only see 2 or 3 fish unless it's feeding time.

Water parameters have been stable, and nitrate and phosphate have been so low between the skimmer and chaeto that we kind of need more fish to ensure the zoox have enough nutrient.

We were planning on taking things slow, but all of the coral has looked so healthy that it's hard to justify waiting beyond "just in case." We had a platygyra bite the dust, but the turbo snails seemed to have a vendetta against that frag unlike any other.

So now I'm paranoid about every little "problem," even when everything looks healthy.

It's hard to say "how much is too much" as it's not a simple "x amount of algae per x gallons of water is the limit".

IMO if you have GHA growing on the rocks in your DT then then either your tank isn't mature and is still bouncing between ugly and nice or you have too much nutrients (probably more often it is a case of both!)

I also just want to point out that IMO (based off what you have said in this thread) it sounds like you definitely don't need more fish to ensure the zoox have enough nutrients. That's not quite how it works.

If you are testing super low nitrate and phosphate but you have algae growing on your rocks, then THAT is why you are testing low nitrate and phosphate, but chances are you don't actually have low nitrate and phosphate. The algae is consuming it and using it to grow, it's NOT because you don't have enough fish.

You will also find that while it certainly helps for corals to be able to filter feed particles and nutrients from the water column they get the vast majority of their "food" from light. I can't remember the exact amount off the top of my head but I think it was upwards of 90%+ of their main food source was light and the remaining nutrients taken from the water column helped with growth and color etc. but coral can still grow fine with minimal nutrients.

'it's hard to justify waiting beyond "just in case.'
I agree, it's hard. But that mentality is exactly what leads to adding too much too soon (I have first hand experience ). It already sounds like you have possibly added too much too soon.

 

[dtruitt]

It's hard to say "how much is too much" as it's not a simple "x amount of algae per x gallons of water is the limit".

IMO if you have GHA growing on the rocks in your DT then then either your tank isn't mature and is still bouncing between ugly and nice or you have too much nutrients (probably more often it is a case of both!)

I also just want to point out that IMO (based off what you have said in this thread) it sounds like you definitely don't need more fish to ensure the zoox have enough nutrients. That's not quite how it works.

If you are testing super low nitrate and phosphate but you have algae growing on your rocks, then THAT is why you are testing low nitrate and phosphate, but chances are you don't actually have low nitrate and phosphate. The algae is consuming it and using it to grow, it's NOT because you don't have enough fish.

You will also find that while it certainly helps for corals to be able to filter feed particles and nutrients from the water column they get the vast majority of their "food" from light. I can't remember the exact amount off the top of my head but I think it was upwards of 90%+ of their main food source was light and the remaining nutrients taken from the water column helped with growth and color etc. but coral can still grow fine with minimal nutrients.

'it's hard to justify waiting beyond "just in case.'
I agree, it's hard. But that mentality is exactly what leads to adding too much too soon (I have first hand experience ). It already sounds like you have possibly added too much too soon.

No gha on the rocks in the DT. The only algae in the DT is green and or brown algae on the glass. Looks like a mix of diatoms, maybe a little coraline, and another greenish to brownish algae that forms spots on the glass. No air bubbles forming on the algae, so I suspect it's not cyano or dino.

 

[MaccaPopEye]

No gha on the rocks in the DT. The only algae in the DT is green and or brown algae on the glass. Looks like a mix of diatoms, maybe a little coraline, and another greenish to brownish algae that forms spots on the glass. No air bubbles forming on the algae, so I suspect it's not cyano or dino.

In that case it sounds fine to me, but still can be caused or made worse by excess nutrients, probably the first sign that nutrients are getting a bit high too. If you are having to clean your glass every day or two it could be a warning sign before your rocks start to grow algae.

But overall some algae on the glass is pretty normal. I would say it slows down for the same reasons that algae on rocks etc. tank maturity.

I would say if you need to clean your glass more than twice a week (and have it look good all week) then your glass algae growth might be a little on the excessive side. But that is very anecdotal and I am sure it's different for every tank.

I would still be very weary of adding too much too soon. You certainly don't "need" more nutrients for coral even if you are testing low nutrients as the presence of algae shows that you have plenty.

 

[dtruitt]

In that case it sounds fine to me, but still can be caused or made worse by excess nutrients, probably the first sign that nutrients are getting a bit high too. If you are having to clean your glass every day or two it could be a warning sign before your rocks start to grow algae.

But overall some algae on the glass is pretty normal. I would say it slows down for the same reasons that algae on rocks etc. tank maturity.

I would say if you need to clean your glass more than twice a week (and have it look good all week) then your glass algae growth might be a little on the excessive side. But that is very anecdotal and I am sure it's different for every tank.

I would still be very weary of adding too much too soon. You certainly don't "need" more nutrients for coral even if you are testing low nutrients as the presence of algae shows that you have plenty.

Excellent. Thank you.