another DSB question

[ultramud]

hi anthony,
i posted this q to ATJ a few days ago(being from oz and all) but he seems to be out for a while.
hoping you can help with my problem??

QUOTE"
hi ATJ
Long time no see, hope all the tanks are all powering on.
i've got a quick question of the water quality nature?
heres some background info,
5*2*@ tank 100l sump * 2
DSB(in tank) has been cycling for 3 months, I added 30kg of cured rock + a bit of live sand 6 weeks ago and the 15 kg of uncured 3 weeks ago.
lights have been up for about 10 weeks, photo = (14 hrs * floros, 2hrs * mh)
skimmer going constantly for 3 months pulling nice thick sludge.
and i only water change once a month (200l)
feeding: around 2 cube's of frozen marine crap/ week(slowed down with the uncured rock)

ive been testing the water weekly with hobby test kits and have been getting good results (nitrates at 0-5 )
i then take a sample to work and get the guys there to test it for me.


sample was taken at 5 in the morning so i expected ph and alk to be a bit wobbly
ph 8.1
alk 141
ca 661
ammonia 0
nitrites 0
phosphates .19
NITRATES 19.4

a bit different from the kits(seachem, dupla, seara)poxy kits
im sure the tank is still cycling but im concerned that the nitrate are an indication of what the tank will be like in the future( maybe i stuffed up the DSB?)any ideas? im also going through a mild but constant cyano bloom is this eating off the nitrates? in my understanding water changes will help in the short term but still 19.4??????
i plan to convert 1/4 of the sump into a macro/micro/?????? fuge in the future to deal with the nutrients from a stocked tank but 19.4????????????? with out any fish

any advice would be muchly appreciated.
cheers
Matt

p.s. can you tell the nitrates are killing me


i should also add that my sand bed is sort of a mixture of 80% ooo marble dust and 20% of 2mm crushed coral mand marble


cheers matt(in the desert in oz)

 

[Anthony Calfo]

Cheers, Matt

'Tis a pleasure to hear from you my friend.

Regarding the nitrate issue... forgive me if this is daft or obvious, but did the techs (or you) reckon the difference in kit reagents testing for the nitrate molecule (nitrate ion verus nitrate-nitrogen)?

The difference is a multiple of 4.4 with most test kit readings needing to be multiplied by a factor of 4.4 to get the actual nitrate level. That would explain a hobby reading of 5ish and a lab reading (better kits) of 20 (actual ppm nitrate).

Some/most of the test kit instructions will describe this and the difference. If it is indeed in your test kit instructions.. it sounds like you did a very American thing (heehee... instructions? we don't need to read no stinkin' instructions! )

For easy and natural nitrate control... I like the use of a sound and deep sugar fine sand bed of 10-15cm (4-6") deep. I'm not a fan of mixing grain sizes at all.

I am adamently outspoken about the casual use of Caulerpa in refugia (it can be a boon or scourge). Rather... opt for a more stable (and useful! regarding maximum microcrustacean culture) microalgae like chaetomorpha "spaghetti algae".

With kind regards,

Anthony

 

[ultramud]

good pick up on the nitrogen, the test kits i have at home do read ions(after reading the instructions thoroughly this time)
ill have to ask the guys at work how they do it. dividing the result by 4.4 does sound better, ill have to check up properly.
i figured that i have taken a reasonable amout of time to let things settle down and establish itself so was a bit upset when
the nitrates came back high.
im not sure which type of macro/micro i will have with the fuge, i still have a fair bit of reading to do with that one.
i probably wont stock the tank with fish(except for a butterfly to handle the aptasia)for another 2-3 months which will be about the time i get the fuge working.
corals: i would like to get going asap as the softies and lps's im my small tank are starting to fight each other fro space.

p.s. with all the tanks i have cycled over the years(marine aswell as fresh) i have never been happy with the test kit results. i have all bar poured ammonia into the water to get any readings for ammonia during the initial cycle never ant nitrites or nitrates.
if i believed the test kits i have a perfect tank everytime and never have to cycle again.

cheers
matt

 

[Anthony Calfo]

Very true about the hobby test kits... I myself tend to favor dry reagents versus liquid (shelf life, accuracy... to generalize). There are few hobby brand test kits I will even spend the time to use. And alas... no one brand has a complete line of "best of" kits. We need to mix and match a bit in this area to get the best kits for each parameter.

If they are available to you in Oz... Lamotte and Hach lines are generally very good, although we pay for that quality.

No worries on the nitrates... the inevitable product of the initial surge/spike in cycling. Occurs worse in some tanks than others... NNR will reduce this in your system in due time (weeks I would expect).

As far as future reading about refugiums and livestock... please forgive the shameless plug ... But:

My new book "Reef Invertebrates" with Fenner has almost 100 of 400 pages dedicated to plants, algae and refugia styles, inhabitatnts & methodologies. All modesty aside... I believe it is the most complete coverage to date on the subject.

Its being released in mere days here in the US from the printer. Short of airmail though, it will actually be another 6-8 weeks (surface mail for affordablility) before the Oz distributors have copies to sell.

Best regards,

Anthony

 

[ultramud]

no worries, thanks for your time anthony.
ill keep an eye out for the book,i think reef online were a supplier over here

cheers
matt