Help! I need some suggestions to fix my dKH levels

[michika]

I need some help solving my low dKH problem. I am aiming for 7 or 8dkH, but can't seem to maintain a reading over 5dKH.

My system is currently running with a kalk. reactor, and I understand that as a result it could be pushing down my levels. So far I have been dosing the maximum of Seachem's Carbonate product almost every day with limited improvement. By limited I mean that I see a move of maybe one point for one day, and then it is back to the normal low levels. I am toying with one of two ideas since manual dosing doesn't seem to be helping me.

1) a Ca reactor. I would have to find a 2.5lb CO2 bottle, but if not I would go with a 5lb.

2) Add in a dosing pump so I can drip in the appropriate additives.

This is a snap shot of what I've been dealing with as far as fluctuations go. Amonia, nitrite, and nitrate are all 0. All of the below measurements were taken between 11am-1pm. The float valve has since been removed from the system, and I am slowly bringing the SG back to 1.024-1.025. I should hopefully be back to where it should be on Wednesday (in two days). The Kalk. reactor maintains Ca at 320ppm, but I'm trying to get it to 380-400ppm. May 24th is the only day that dKH wasn't added to the system. On that day I dosed to boost the calcium levels.

Date Time Temp pH SG Ca dKH Mg
20-May-07 PM 82.1 8.1 1.025 5 960
21-May-07 AM 79.7 7.8 1.022 320 6 1080 Float valve failed
22-May-07 PM 82.9 8.0 1.024 320 4 990 Added on kalk. reactor
23-May-07 AM 80.2 8.0 1.024 380 6 990
24-May-07 AM 80.2 8.1 1.022 300 6 900 Float valve failed
25-May-07 PM 82.6 8.1 1.022 380 5 960
27-May-07 PM 80.2 8.0 1.022 320 4 900
28-May-07 PM 81.5 8.0 1.023 340 4 960

I'm not sure how to proceed as I've never had such low levels before. Everything in the tank looks to be doing well. I'm seeing lots of new colors coming out on my SPS, my clams are always open. Livestock thankfully wasn't harmed by the float valve failures, and all still retain big appetites.

Help?

[Ruth]

The first thing that jumps out at me is that your magnesium levels are low. I would try and get that up to 1350 - 1400 (over time of course but you already know that). That could very well be what is causing your other levels to be out of whack.
If it were me I think I would be just tempted to stop dosing Kalk altogether for a while - stop adding any kind of buffer and just do larger water changes - like maybe 40% every 4 or 5 days and see if this does not bring everything back into balance. Is there any chance that you got a bad bucket of salt? Have you tried to measure what levels your fresh mixed change water is?

[michika]

The salt I use naturally has low dKH, I should have mentioned that. I'm not really open to changing my salt brand just because I have a full bucket right now.

I actually have been dosing Mg regularly as well (8 hours apart from the alk.), and its barely doing anything. I do have 2 mangrove plants in my sump, and I know they take up quite of Mg. You can see the rise in Mg the day after I dose.

I do 5g water changes ever week, and lately (in the last two weeks) have bumped it to 10g. Again because of the low dKH levels in my salt I feel its contributing to the problem.

These are the levels I got from freshly mixed up saltwater with RO/DI:

Red Sea Coral Pro Salt
SG 1.025
Mg 900
Ca 460-480ppm
dKH 6 or 2.2-2.6 meq/L

I'm afraid to stop dosing dKH for fear of it dropping below 4. What do you think would happen if I stop dosing? Would the levels continue to drop? I wouldn't mind stopping dosing, actually it would probably nice to do one less thing each day.

So if I understand, your recommendation is to work on raising my Mg levels, and in the mean time to stop dosing alk.

[ClubReef]

Hi Katherine,

I remember reading Randy Holmes-Farley's article on the relationship of Calcium and Alk...

In the section labelled "Apparent Excess Demand for Alkalinity" he says,

"If an aquarist is supplying a balanced additive to his aquarium, and calcium seems stable but alkalinity is declining, it may very well be that what is needed is more of the balanced additive, not just alkalinity. "

Perhaps your tweaking with the buffer is becoming counter-productive. Try doing some water changes and get back on a balance dosing schedule..or if you are on a reactor..try adjusting the dosage.

You can read his article here:
http://www.reefkeeping.com/issues/2004-12/rhf/index.php

Hth

[danny zubot]

Perhaps your ALK additive is defective. Have you tested it? Have you ever tried to use the 2 part home made additive?

[michika]

I'm using Seachem's Carbonate product in liquid form. It does work, its just not having a staying power. There is a upward movement in dKH after dosing, I just can't get the levels high enough, or get them to stay. I also tested just the product in freshwaster (before dosing), and it gives me a high dKH reading. I assume that means my product is okay.

I think I also need to do something about the fact that the salt I'm using starts out with low dKH. How do I address this?

I have tried using Baking Soda in the past, granted it was on a larger system, and I had to dose continually with it as well. At that time I was using a different salt brand.

So to sum up the suggestions so far:
- stop dosing to raise dKH, and instead focus on raising my Mg levels.
- look into if my additive is defective. Done.
- change the dosage in my reactor. Does this mean change the drip rate, or the strength of the additive entering the water?

I'm starting to think my problem is that I'm starting with low dKH (thanks to my salt mix), and once that is in my tank a lot of it, and the Ca is being used up because the tank is filled with SPS, and clams.

I guess the question is now how is the best way to raise and keep my dKH at appropriate levels? A reactor? A dosing pump?