Raising Alkalinity

[Michaelf63]

Can anyone give some advise on trying to raise the alkalinity I have been adding Seachem Reef Builder over about 5 days at 36 grams a day used aprox 200 grams and the alk has risen from 7 to 9 but wont go any higher so I have stoped adding it. The tank is 400litres with 100kg live rock, sump is 100litres with 4kg matrix media phosguard and purigen pre filtered with sponge and media.The refuge is 100 litres with about 3 kg live rock and various caulerpa. The system has been running for a month. Calcium 440,nitrate 0 nitrite 0 amonia 0 phosphate 0, PH 8.4. Lighting on tank 2 x 150w 10k halide 1 x 150w 20k halide 4 x 39w actinic HO fluro. Refuge 1 x 39w actinic 1 X 1000K Aquastar Furo.

 

[bertoni]

[welcome]

The tank probably just needs more supplement, although 36g per day is a lot. That should be around 40 ml? This calculator will help with dosing guidelines:

http://home.comcast.net/~jdieck1/chem_calc3.html

It does require a guess as to the water volume of the tank.

Are there any signs of abiotic precipitate? Is there a whitish chalky buildup on any surface?

 

[Michaelf63]

There is no build up on any thing tank looks great algae bloom has subsided water is crystal clear. Salinty which I did not mention is 1.0227 and I also run a 25 watt uv.

 

[bertoni]

Is there a lot of stony coral or coralline algae growth? The the animals are doing well and there's no sign of precipitation, then I wouldn't worry much. A magnesium test result might be interesting, but low magnesium probably is not the issue.

I did manage to get the wrong volume estimate for the system, but that's still a fair amount of supplement.

 

[Michaelf63]

There is a good amount of purple coraline and it appears to be growing rapidly no stony coral yet however there is a few morphs which dont seem to be opening very well.I have a pipe organ coral which is doing fine and a brain coral which was on the live rock which was almost dead but has come back and growing well.

 

[bertoni]

Hmm, I'm not sure, but I wouldn't worry much if there's no signs of precipitation. You might want to check the internal parts of your pumps, if that's easy to do.

 

[MCsaxmaster]

I'd get a magnesium reading if for no other reason than to rule out low magnesium as a possible problem. I wouldn't necessarily say it DOES sound like a problem, but it would be nice to be sure it isn't

 

[Michaelf63]

Thanks really appreciate the advise will test for magnesium. Also tested my salt before adding to tank which is Red Sea and the alk is actually lower again then my tank. Could it be due to having a plenum with 30kg of crushed coral and 30 kg of agronite in the main tank and 30 kg of agronite in the refuge.

 

[bertoni]

I suspect the Reef Builder doses are raising the SG.

 

[bertoni]

Well, that was dumb. I think the doses are raising the alkalinity, not the SG. Sigh.

 

[Michaelf63]

Thanks Jonathon I have also read that Reef Builder will only maintain Alk and wont raise it is this true because maybe I should try another product as I am still adding the Seachem product and the Alk wont budge.I will see if I can purchase a Mag kit today though they dont seem readily available here in Newcastle.

 

[bertoni]

Reef Builder can be used to raise alkalinity. I've done that mysefl many time. How much is being added, and how long after adding it are you measuring alkalinity?

 

[Michaelf63]

I am adding 18grams in the morning and testing in the afternoon then adding another 18 grams after testing and retesting the following morning so on.

 

[bertoni]

That's not a very large dose. I suspect the corals are capable of consuming the alkalinity added before you're testing. I'd try testing after a half hour, and even then, that's a small change for an alkalinity test kit to detect.

 

[Icefire]

Well the calculator say for 300L water to raise by 2dKh you need 18grams exactly. You need to watch the PH as it will rise.

If you loose something like 1dKH/day, you need to dose 9gram/day just to keep it stable.

Test the alk every day to know how much is beeing consumed and dose it.

If you want a cheap and effective way to dose alk, use baking soda.

 

[bertoni]

Assuming 100 g (380 L) of water, I get 11 g of Reef Builder (as opposed to Reef Buffer) to raise the alkalinity 1 dKH. He's got a 400 L tank with a 100 L sump and a 100 L refugium.

 

[Michaelf63]

Is it possible for a newely estabilished tank with the main consumer of Alk being coraline algae a organ pipe coral and a few morphs could consume this much Reef Builder. The label on the 300 gram container says it can treat 4800 gallons.

 

[bertoni]

Yes, definitely. Coralline algae can consume a huge amount of calcium carbonate.

 

[Michaelf63]

Thanks guys I will just keep adding it until I run out then I will switch to the two part recipe in reef keeping online to save on costs as the seachem products are very expensive in Australia.