What's is stable alk?

Discussion in 'SPS corals' started by Mordim, Feb 6, 2019.

  1. Mordim

    Mordim TCMAS Event Committee
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    What is an acceptable variance of alk within a day for it to be considered stable?

    I know stability is key is important. I've also read to test your alk at the same time each day as it can vary naturally at different times of the day. How much variance is ok?

    If I manually dose dissolved soda ash to correct alk while trying to dial in Doser, how much can I raise it in one dose and not piss off my sps?
     
  2. csb123

    csb123 Senior Member
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    I don’t know if there is a definition for stable alk. Mine varies by 0.3 weekly due to a variety of causes. In a 24 hour period it varies by 0.1. I dose kalkwasser, about 2/3 during the day during high uptake lights on period, and 1/3 over night to maintain pH. I also, run a calcium reactor continuously.

    If my alk is a bit low, I add sodium bicarbonate. If it is a bit high, I turn off my calcium reactor for a while.

    I think the objective is to avoid big rapid swings, which stress the corals.
     
  3. OP
    Mordim

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    My sps are showing signs of stress by slowly bleaching over weeks . The polyps are there and extended but white. I think it has to do with alk settings from what I have read as most likely candidate. Additionally, I dosed some soda ash recently and it accelerated. I only dose a little Kalk by doser throughout the day but not at night. I wonder if not dosing at night is causing you big a swing. I'll try to measure at several times throughout the day on Saturday to see.
     
  4. csb123

    csb123 Senior Member
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    Good idea. That’s what I did. Check the alk several time over 24 hours. If you haven’t already, fire off a Triton test.
     
  5. Reefking

    Reefking Senior Member
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    A few questions...
    what size tank?
    Is your water temp constant day and night?
    How long have you been running this tank?
    What is your current alk levels?
    Do you have good water flow within the tank?
    What lights are you running and how many hrs per day?
    Are your sps corals high or low in placement? What type of sps do you have?
    Where these sps corals purchased recently? If yes, aquacultured or wild?
     
  6. H2OHOH

    H2OHOH Senior Member
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    Give the Reefking a stool and urine sample and he will solve your alkaline issues
     
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  7. csb123

    csb123 Senior Member
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    You do need to examine the patient before you prescribe a treatment...
     
  8. OP
    Mordim

    Mordim TCMAS Event Committee
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    75ga display w/40 ga sump. Running since spring. (4 months lights out cycle)
    18"x18"x12" fuge with chaeto & Kessil H380 (On 23:00 to 02:00 & 04:00 to 07:00)
    Reef Octopus INT 110 classic skimmer

    Apex controller (last 2 days)
    upload_2019-2-8_16-8-14.png

    Alk tested today at 7.3 dkh I try to keep it around 7.8 dkh to match Tropic Marin Pro reef salt mix. I'm working on autowater change. Mixing station just completed. Now need to run hose for DOS water change. planning 1-2 ga change per day.
    I have a BRS Doser set up to a 1 gallon kalk solution (1 ga rodi water mixed with 2 tsp kalk).

    Kalk_Doser outlet:
    Fallback OFF
    OSC 000:00/015:00/045:00 Then ON
    If Time 23:00 to 08:00 Then OFF
    If Output ReturnPump = OFF Then OFF
    If pH > 8.30 Then OFF

    Here are my measurements. You can see that my Alk is continually falling. I'm dosing kalk such that calcium is rising. I manually adjust alk with manual dosing to bring it back to 7.8-8 dkh. I try not to raise by more than 0.5 dkh in one day.
    I started dosing a little KNO3 & KPO4 each week to get detectable N & P. It didn't make a difference in coral but now I'm getting hair algae. I feed heavy with LRS & reef chili so the corals probably had sufficient N & P from that. I'm thinking of stopping dosing the KNO3 & KPO4 to see if it makes a difference to coral or algae. Algae is not bad: green rocks and sprigs here and there of hair. Clean up crew mostly keeping up. I haven't wanted to increase kalk more since calcium is not rising with kalk dosing while alk falling. I might have to set up a alk doser too with soda ash.

    upload_2019-2-8_16-17-43.png

    Flow is good. I have a jabao PP-15 at each end of the tank, I have them alternate back and forth all day between 15-40% controlled by my apex.
    Return pump is 3-5x turn over.

    Display lights are Kessil A260w tuna blues
    upload_2019-2-8_16-26-17.png

    Corals are a couple of mushrooms, toadstool, hammer coral, couple of acans, a favia, a blasto, alien eye chalice (suffering the most), blue tort sps, red monti with purple dots, some orage cloves. Softies & lps looks great except chalice (receding tissue skeleton showing) & monti (very pale, hard to tell if alive or just algae colored), and tort starting the slow bleaching I mentioned. However, softies and lps are slow to now growth despite looking happy. Most of these corals I got at the fall expo.
    Chalice is in slightly shaded area on sand bed. It was doing poorly in light area. I moved it to shaded and it recovered. Now it's suffering again.
    monti half way down rock and 2/3 of the way back.
    Tort on top of rock. 6" between tip of tort to water level. 8" from lights to water.

    2 small/med. clowns, 1 goby/shrimp pair, 1 rose urchin, 6 troch. snails, and 1 emerald crab. A fair number of pods.
     
  9. OP
    Mordim

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    My test kits are red sea.
    I just picked up hanna alk checker. I used that for today's alk test.
     
  10. OP
    Mordim

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  11. Reefking

    Reefking Senior Member
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    Great details outlined above.

    My initial thought is that the alk Doser with soda ash would provide less swings with the alk. I think you are on the right track with the alk focus.

    Hoho still has his apex on his floor!
     
  12. OP
    Mordim

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    Thx. I sent a Triton test out last weekend. I'm still waiting on the results.
     

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