View Full Version : Could my live rock be leaching nitrates
youpey
06/08/2011, 08:09 AM
My tank has been setup for almost 2 years now. there was a short time where i was doing water changes one time per month instead of weekly. When i realized my nitrates went through the roof, i did everything i could to lower them. I removed the crushed coral substrate with live sand. i changed 100% of the water over a 2 or 3 week period. typically 1 to 2 gallons per 1 or 2 days.
Now my nitrates went from off the chart to currently it is at around 25 to 40 or so, but i would like to get it to below 10. I have kept up on my water changes to weekly, i have reduced feeding to 1 time per 2 days. I checked the distilled water i make before putting it in the tank and it is less then 5, not 0, but less then 5.
In addition, I changed out my filter media completely and have started changing the filter floss daily or 2 days, whenever i see any brown on it. I have also installed a biocube skimmer, which still hasnt started working yet, but i think it has only been 1.5 weeks and i heard they take 3 weeks to begin working
i am not overfeeding and i try my best to remove any large uneaten pieces of food.
My water changes are as follows, take a turkey baster and blast the live rock to get anything, then pull the water out near the rock. At this point there isnt must stuff on the live rock when i blast it. I have also vacuumed out the back chambers.
at this point i am at a loss. My nitrates are still higher then i would like, and i tried 2 different test kits, both came out pretty close to each other. Is it possible nitrates are leaching from the live rock, if so how do fix this without buying all new rock. oh and i added more flow with a powerhead
any ideas would make me happy
Randy Holmes-Farley
06/08/2011, 08:57 AM
Nitrate does not bind to rock or sand. Unless there is ongoing decay of dead organisms attached to the rock (or detritus settling onto it), they are not a source of nitrate.
These may help:
The “How To” Guide to Reef Aquarium Chemistry for Beginners,
Part 4: What Chemicals May Detrimentally Accumulate
http://reefkeeping.com/issues/2007-09/rhf/index.php
Nitrate in the Reef Aquarium
http://www.advancedaquarist.com/issues/august2003/chem.htm
disc1
06/08/2011, 09:00 AM
What test are you using?
Like Randy said, there is no way the nitrate is leeching from the rocks themselves, but that doesn't mean there's not detritus and dead stuff in the cracks and crevises of the rock that are the source of the nitrate.
goldmaniac
06/08/2011, 11:30 AM
... does the same hold true for phosphates? I always thought that phosphates can be bound in the rock and leeched out, and I'm just interjecting while we have Randy on this thread to find out this for sure.
of course, nitrates and phosphates are very different. I'm just asking for clarity..
sorry to hijack the thread -
youpey
06/08/2011, 11:32 AM
i have used the API and the salifert test kits. The salifert test kit says it expires next month and the API doesnt have an expiration date but i have had it for 2 years
if it isnt in the rock, i wonder where else it could be coming from...or maybe just old test kits causing inaccurate results??
goldmaniac
06/08/2011, 01:53 PM
I would buy a new test kit. From what you're describing, with mature live rock, and with nutrient export at the level you're doing, it sounds like water changes should be able to keep the 'trates in check.
Randy Holmes-Farley
06/08/2011, 02:52 PM
... does the same hold true for phosphates? I always thought that phosphates can be bound in the rock and leeched out, and I'm just interjecting while we have Randy on this thread to find out this for sure.
Phosphate does bind directly to calcium carbonate rock and sand. I discuss it here:
http://reefkeeping.com/issues/2006-09/rhf/index.php#10
from it:
A second mechanism for potential phosphate reduction when using high pH additives is the binding of phosphate to calcium carbonate surfaces. The absorption of phosphate from seawater onto aragonite is pH dependent, with the binding maximized at around pH 8.4 and with less binding occurring at lower and higher pH values. Habib Sekha (owner of Salifert) has pointed out that limewater additions may lead to substantial precipitation of calcium carbonate in reef aquaria. This idea makes perfect sense. After all, it is certainly not the case that large numbers of reef aquaria exactly balance calcification needs by replacing all evaporated water with saturated limewater. And yet, many aquarists find that calcium and alkalinity levels are stable over long time periods with just that scenario. One way this can be true is if the excess calcium and alkalinity, which such additions typically add to the aquarium, are subsequently removed by precipitation of calcium carbonate (such as on heaters, pumps, sand, live rock, etc.). It is this ongoing precipitation of calcium carbonate, then, that may reduce the phosphate levels; phosphate binds to these growing surfaces and becomes part of the solid precipitate.
If the calcium carbonate crystal is static (not growing), then this process is reversible, and the aragonite can act as a reservoir for phosphate. This reservoir can inhibit the complete removal of excess phosphate from a reef aquarium that has experienced very high phosphate levels, and may permit algae to continue to thrive despite all external phosphate sources having been cut off. In such extreme cases, removal of the substrate may even be required.
If the calcium carbonate deposits are growing, then phosphate may become buried in the growing crystal, which can act as a sink for phosphate, at least until that CaCO3 is somehow dissolved. Additionally, if these crystals are in the water column (e.g., if they form at the local area where limewater hits the aquarium water), then they may become coated with organics and be skimmed out of the aquarium.
If phosphate binds to calcium carbonate surfaces to a significant extent in reef aquaria, then this mechanism may be attained with other high pH additive systems (such as some of the two-part additives, including Recipe #1 of my DIY system). However, this potential precipitation of phosphate on growing calcium carbonate surfaces will not be as readily attained with low pH systems, such as those using calcium carbonate/carbon dioxide reactors or those where the pH is low due to excessive atmospheric carbon dioxide, because the low pH inhibits the precipitation of excess calcium and alkalinity as calcium carbonate, as well as inhibiting the binding of phosphate to calcium carbonate.
goldmaniac
06/08/2011, 09:46 PM
Thank you very much, Randy!
Randy Holmes-Farley
06/09/2011, 04:57 AM
:thumbsup:
Happy Reefing. :)
Ron Reefman
06/09/2011, 07:00 AM
I have kept up on my water changes to weekly, i have reduced feeding to 1 time per 2 days. i am not overfeeding and i try my best to remove any large uneaten pieces of food. any ideas would make me happy
First you say you aren't over feeding... then you say you are removing any large pieces of uneaten food...
That sounds alot like over feeding to me. Feed much less every day. If ALL the food isn't gone in 2 minutes, you are over feeding.
Orcrone
06/09/2011, 07:05 AM
i have used the API and the salifert test kits. The salifert test kit says it expires next month and the API doesnt have an expiration date but i have had it for 2 years
The API kit has 0 as its lowest reading and then jumps straight to 5. I think the kit is fine for a FOWLR tank but for a reef you want better resolution than the API kit will give you in the low range.
redmarble
06/09/2011, 01:30 PM
First you say you aren't over feeding... then you say you are removing any large pieces of uneaten food...
That sounds alot like over feeding to me. Feed much less every day. If ALL the food isn't gone in 2 minutes, you are over feeding.
+1 on this.
youpey
06/09/2011, 03:07 PM
+1 on this.
i feed rods food. sometimes there are larger pieces of food in there, i guess that didnt blend. all i meant was that any large pieces are fished out since the fish wont touch it
by large pieces i mean the size of pieces, not quantity of the pieces
NatureNerd
06/09/2011, 03:44 PM
If you truly only have the one clownfish, you really only need to feed what it can eat in twenty or thirty seconds, if that. Nothing should ever settle on the rocks or substrate. I agree that you just might be overfeeding.
NatureNerd
06/09/2011, 03:49 PM
Also, you are right in removing any mechanical filtering for cleaning every couple of days. A floss bed is a great trap for decaying old food and waste products. Swapping it out for clean every couple days is always a good idea.
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