I've been going back and forth on the best ALK level for a ULNS SPS system. Most reading seems to suggest you must run a lower level of ALK due to less nutrients in the water, ie 7.0DKH. Anyone have any experience running a set up with ulns, 0 point of sale, 0 nitrates. I, of course, would like to get my nitrates up but even with dosing I haven't been able to do it and I don't want jeopardize my tank by doing any thing too quick. Just looking for some advice on when it comes to growing sps in a ULNS environment. Thanks, Rich
Best ALK Level For ULNS
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Every tank is different, and it will take some experimentation as to what that level is for you and your tank. IMO, I agree that lower Nitrate/Phos should equal running lower alk for acros. My Nitrate/Phos run 5/0.05 and I keep my alk between 7-7.5 and my acros love it.
I keep my Alk between 8.8-7.8. I dose 2 part in the morning usually 10ml because my system has really settled in and started growing like crazy and dropping 1dkh per day. My po4 is never over .03 (Hannah) and no3 never over 5 ( salifert) but usually I struggle to read anything over 0 and Have a small wisp of hair algae. I would consider my system a ULNS although I never planned that. I have not seen any negative effects of dosing 10 ml alk a day or keeping my tank in that range. As a matter of fact all my Sps is starting to encrust so bad I’m about to have a war zone. For a while I kept my Alk around 9.5 and I had hardly any growth that I have now and my corals always looked stressed by the end of the day. Hope that helps. If you have any other questions holla back!
Yeah its been really interesting and sometimes frustrating. I'm currently running 7 but everything seems to be really not growing. Corals seem to be hibernating. I've adjusted my PAR down, I've read that high PAR without nutrients isn't a good combo so I'm trying to keep my levels around 300PAR(they were, in the high spots, 400-450). I'm dosing acropower daily and feeding my corals every other day with reef roids/reef chili/etc. I actually turned off my skimmer about a week ago to see if nutrients would raise but so far no. I believe my live rock/marine pure blocks are just exporting nutrients extremely fast. I've, of course, double checked all my levels with multiple test kits. BTW I do have two flasher wrasse in the tank but they aren't really producing much waste to tip the scales in nutrients. Just trying to pick others brains who have ran similar setups to see if I can get a baseline on where to start/what to look for.
What size tank and how new is it? Sounds like a combination of new tank syndrome and not enough fish.
That's really interesting. I've read other info that ppl have done that as well, run what would be considered to high ALK for ULNS and have had zero issues/great success. That's what makes it so frustrating is to try and figure out where to start/aim for with ALK then adjust from there. I know to do everything slowly with alk as any change in a reef system but I'm trying to get a idea of what to run. I think red sea says they recommend a 7ALK on their "recipes" for reef tanks. But it doesn't really say about PAR, which I've read should be adjusted lower if you have ULNS. I have nothing "wrong" with my tank but I know I should be getting better growth from my SPS.
Tank is over 2 yrs old, actually coming up on its 3rd year. 105 gallon tank I believe or might be 115. I had to go fallow about 6 months ago due to ICH. Now I have two flasher wrasse in there and more fish finishing up QT. Tank has always been feed/dosed with nitrates when going through fallow. Tank still always had inverts in it also, 3 cleaner shrimp, fire shrimp, numerous snails/hermits so was always being fed. I actually am starting to think my export is too strong at getting rid of nutrients. Between live rock, marine pure blocks, algae scrubber, I think its really exporting nutrients fast.
Yep, start building back up your fish count and reduce your exporting. On my 4 year old tank, the only exporting I use is water changes, a skimmer, and occasionally gfo. And I'm packed with fish.
road_runner
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I keep my alk 6.7 to 7.2.
I run natural sea paramaters level and UNLS.
Be careful though, when you run ULNS sps are more sensitive to alk swing...
rynosreef
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I like to think of it like this... If nitrate/phosphate levels are indicators of the available nutritional content of the water, then low levels of these should coincide with lower levels of other elements that push growth, ie lighting and alk.
What's your current alk reading and how long has it been there? How long have you been getting readings of 0 for no3 and po4?
If you'd like to raise your nitrate and phosphates, you can try feeding more of course, adding fish, or maybe putting your algae scrubber light on a limited photo-period such as only a few hours a night. Algae scrubbers/algae reactors can strip the water of nitrate/phosphate pretty efficiently.
What's your current alk reading and how long has it been there? How long have you been getting readings of 0 for no3 and po4?
If you'd like to raise your nitrate and phosphates, you can try feeding more of course, adding fish, or maybe putting your algae scrubber light on a limited photo-period such as only a few hours a night. Algae scrubbers/algae reactors can strip the water of nitrate/phosphate pretty efficiently.
29bonsaireef
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My current system is LN. Driven by natural export methods. Though I did use po4 remover close to a year ago, to knock it down really low. Last I checked no3/po4 were still undetectable. I try to never let alk go above 7.5, this works for me. My par is not low.. bottom of my tank is in the 300s, corners 250, top of rocks 650+. I have no issues with growth at these levels. I'm not seeing corals grow at mind blowing rates, but I would consider it average. I do have close to 20 fish, though. Display is 150 gallons.
Yeah I'm always really careful/catious whenever I make adjustments in my tank. I go with the old saying slow is fast, especially in this hobby. I'm going to keep a eye on everything and as fish get added make adjustments if needed. I think for now I'm going to keep my ALK around 7.0-7.2 and see how it goes.
It's at 7.0 via Hanna checker. It's been fluctuation between there and 6.8 for awhile. I do dose two part when I see it get around 6.8. So I would say my overall avg is 6.8 to 7.2 for months. 0 for nit/phos has been as long as I can remember. Maybe once on my hanna ulr checker I saw .001(think that's how many zeros where in front, its been a long time). Color tests like salifert/red sea/tropic marine, never show color. So it's been pretty status quo for a long time.
Like it has been said what’s good to the goose is not necessarily good for the gander. My corals might of been hurting when my tank was at 9.5 and being in the mid 8’s is good for them because they where already accustomed to being higher. Starting low and working up is a lot harder to get used to then high to lower. Lower nutrients usually means clearer water so par can penetrate better causing the corals to crave more alk (and no3/po4). I am currently working on a coral translator so I can just ask them and know for sure[emoji57] higher alk has been shown to speed up growth to a certain point but once you cross that they seem to bleach quickly and die. I think they will get used to most levels if you go slow enough, they are adaptive animals after all and are designed to change if needed. In the ocean nothing really happens fast.
In my 80g I have the following in adult sizes (blue tang is only about 5"):
1 Blue Tang
4 Lyretail Anthias
2 Green Chromis
2 Clownfish
1 Black Cap Gramma
1 Bangaii Cardinal
Punchanello
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Your story is very similar to mine. Age,, going fallow, low nutrients etc. I don't have the answers but I do know that even minor changes to alk have caused colonies to STN under these conditions and growth and colour have suffered a lot. I am currently experimenting with reducing the light from the LEDs in my hybrid set up and increasing my bioload.
Mrfats4001
New Member
I’m new to reefing my all is 11.5 is this too high and if so how can I lower it
