As mentioned in an earlier post, my 75 gal reef tank has been up and running very successfully for 4 months or so, lately my coral sand has become covered in an ugly brown algae, even on syphoning out much of the sand, cleaning it and then returning to tank, the algae returns within a week. Phos levels v low, lighting 4 T5's on for 12hrs daily, any thoughts
nuisance algae
- Thread starter Lloyd
- Start date
Diatoms or cyanobacteria.
Anyway I would guess you might need
1. a better protein skimmer
2. more circulation
3. better water (RO)
4. higher salinity inhibits cyano (>1.023,1.024)
5.higher pH
6. More water changes
Algae needs light and food to grow, and believe me cutting down on light is not the way to go in a reef or any other tank. Get the nutrients out!
Anyway I would guess you might need
1. a better protein skimmer
2. more circulation
3. better water (RO)
4. higher salinity inhibits cyano (>1.023,1.024)
5.higher pH
6. More water changes
Algae needs light and food to grow, and believe me cutting down on light is not the way to go in a reef or any other tank. Get the nutrients out!
thanks for your thoughts wayne, RO not an option at present - could push up PH perhaps (8.3 at present), also sp grav is 1.023 and so could increase that - what do you think about temperature?, it's been up all summer 27.5C av . I think my skimmers pretty good and I change 5 gal per week although nitrates always nil due to caulerpa in 30gal sump
pH 8.3 is good, so pushing it up higher is not an option I'd explore at the moment. Ditto SP is ok, 27.5 is perfectly normal.
5 gals a week on a 75 is not much in all honesty, what skimmer do you have, how much are you pulling out - a cup a day - that is the real benchmark for GOOD skimming, even on understocked systems (it is surprisingly high, but true). I don't doubt you have zero nitrates as you have a variety of algaes to consume it, but without nutrients you will not have algae and as you have an algae problem you must have some nutrients.
How much floor space in the tank, how much rock, how much rock covering floor space, how deep sand, how often hoovered.
Also how much circulation?
5 gals a week on a 75 is not much in all honesty, what skimmer do you have, how much are you pulling out - a cup a day - that is the real benchmark for GOOD skimming, even on understocked systems (it is surprisingly high, but true). I don't doubt you have zero nitrates as you have a variety of algaes to consume it, but without nutrients you will not have algae and as you have an algae problem you must have some nutrients.
How much floor space in the tank, how much rock, how much rock covering floor space, how deep sand, how often hoovered.
Also how much circulation?
I would have thought that if nutrients were being introduced to your tank through your (non RO) water supply, you would've experienced a diatom bloom much sooner than you are - not 4 months in.
So saying, switching to RO water did clear up my diatomaceous brown alage although I almost miss it now. With little actual 'live' rock, my tank currently looks quite sterile.
So saying, switching to RO water did clear up my diatomaceous brown alage although I almost miss it now. With little actual 'live' rock, my tank currently looks quite sterile.
Here's the technical spec and some answers to your other questions
Skimmer is a Red Sea Prizm, 100gal, I doubt if I extract even a cupful a month, never mind per day?
2 x Maxi Jet 1100 litre/hr power heads - both near the top of the tank at opposite ends, 1 front 1 back, also some movement from the spray bar of the eheim 2329 external filter ( I know the external isn't really necessary with my sump and live rock - but I also know that I need to buy some more rock when funds permit)
Regarding my rock, since I don't have that much, poss 40lbs or so, I do have a fair area of sand - again this is the reason the brown algae bothers me so much - poss 30% of the tank bottom is sand - only 1/4 inch deep max though
Regarding RO - where I live in the UK (Cornwall) has the highest water taxes in the land so running an ROunit 24hrs/day is fairly costly - maybe one day.....
Skimmer is a Red Sea Prizm, 100gal, I doubt if I extract even a cupful a month, never mind per day?
2 x Maxi Jet 1100 litre/hr power heads - both near the top of the tank at opposite ends, 1 front 1 back, also some movement from the spray bar of the eheim 2329 external filter ( I know the external isn't really necessary with my sump and live rock - but I also know that I need to buy some more rock when funds permit)
Regarding my rock, since I don't have that much, poss 40lbs or so, I do have a fair area of sand - again this is the reason the brown algae bothers me so much - poss 30% of the tank bottom is sand - only 1/4 inch deep max though
Regarding RO - where I live in the UK (Cornwall) has the highest water taxes in the land so running an ROunit 24hrs/day is fairly costly - maybe one day.....
Many supermarkets in the States have water vending machines that allow you to fill 5 gallon jugs with RO water for $1.25. I haven't been back home to England in a couple of years so I'm not sure if this is the case there. Give Tesco's a try. Finding one would mean you would not need a costly RO unit in your home.
Did you say you've had your tank setup for 4 months and are only now suffering the unsightly algae? If the source of the nutrients which are feeding the diatoms is in fact your water supply, I would have expected the bloom to flair up in the second week of your tanks setup - not 4 months down the line. Makes me think the water is not the problem (I am new to SW though, so take all I say with a pinch of salt).
I believe that diatoms are caused by high silica and phosphates. These can be removed by nutrient removing filter bags placed in your Ehiem, although they would only treat the symptoms, not the cause. Might still be an option because if it is taking a week for the diatoms to return after syphoning, I don't believe your nutrient levels to be obscenely high. Again, a pinch of salt applies (no pun intended).
Did you say you've had your tank setup for 4 months and are only now suffering the unsightly algae? If the source of the nutrients which are feeding the diatoms is in fact your water supply, I would have expected the bloom to flair up in the second week of your tanks setup - not 4 months down the line. Makes me think the water is not the problem (I am new to SW though, so take all I say with a pinch of salt).
I believe that diatoms are caused by high silica and phosphates. These can be removed by nutrient removing filter bags placed in your Ehiem, although they would only treat the symptoms, not the cause. Might still be an option because if it is taking a week for the diatoms to return after syphoning, I don't believe your nutrient levels to be obscenely high. Again, a pinch of salt applies (no pun intended).
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You have a fat chance of buying RO at a supermarket in Britain though some lfs's sell the stuff - see if yours does. I am totally unfamiliar with the local shops in Cornwall I'm afraid so I would jsut phone around some local marine stockists and see if they'll sell you RO water. I would imagine your tap water is going to be pretty loaded with silicates, though it depends where in Cornwall you live.
Frankly speaking your skimmer is grossly overloaded and you need a better one. Join something like ultimatereef.net and look in the ads there or on ebay and see if you can get one that is going to be upto the job like a Deltec MCE600 or an aquamedic. The prizm is good for tanks to 20, 30 gallons , no more. I know, I have one. However, I am still hauling out a bunch of stuff from mine, implying you need to tune yours anyway till you get a new one.
Your sand depth seems reasonable. So at least that's not a problem
Frankly speaking your skimmer is grossly overloaded and you need a better one. Join something like ultimatereef.net and look in the ads there or on ebay and see if you can get one that is going to be upto the job like a Deltec MCE600 or an aquamedic. The prizm is good for tanks to 20, 30 gallons , no more. I know, I have one. However, I am still hauling out a bunch of stuff from mine, implying you need to tune yours anyway till you get a new one.
Your sand depth seems reasonable. So at least that's not a problem
ok the general consensus seems to be I need a better skimmer and to start using RO, in fact I've been researching the latter, I had thought that you needed to run an RO unit continuously and since the smallest use 50gal/day, that would add up to a lot of wasted water, in fact, this now seems not to be the case, so in the near future I shall be buying one!
thanks for all your comments
thanks for all your comments