clumping GFO and GAC--need suggestions

[tmc1313]

Hi guys, I was dosing Randy's two part (recipe 1) into my sump alongside my GFO/GAC dual reactor. My GFO was turning white after a while and if not changed out would clump along with my GAC. I moved the dosing pumps (upstairs) to the DT so it would be far away from my reactor (downstairs), but this hasn't solved my problem (still clumping). Any suggestions about this? I'm already up to dosing 300ml a day of each and my tank (mostly SPS) is still quite young. Switching to recipe #2 might help, but then I would be dosing ~600mls just to keep levels up. My concern is with the tank still so young and growing I will be dosing a liter a day if not more soon. So, what do you think, calcium reactor on the horizon?

[Reeferhead]

How big is your tank? Your probably dosing too much or in unbalanced proportions. I had the same problem. I recalibrated my dosing pumps and brought my dosing down from 300mL/day to 100mL/day over the period of a few weeks. No more GFO clumping, Alk and Ca are stable, and my SPS are growing faster than ever.

[tmc1313]

144 half cylinder with a 40 gallon sump (half full). I'm dosing equal amounts of each. My levels seem fine, I'm at Ca = 420, Alk = 9 and Mg = 1450 (coming down after I raised it to combat some brysopsis).

[Reeferhead]

My levels appeared fine as well. FYI my tank is a 150 with a 60 gallon sump. With a such a young tank I would bet 10 to 1 odds your dosing too much, FWIW

[bamf25]

How big is your tank? Your probably dosing too much or in unbalanced proportions. I had the same problem. I recalibrated my dosing pumps and brought my dosing down from 300mL/day to 100mL/day over the period of a few weeks. No more GFO clumping, Alk and Ca are stable, and my SPS are growing faster than ever.

Is this dosing 100 each of Calcium and alk, or 100 mls total meaning 50 calcium + 50 alk?

[Reeferhead]

100 each

[bertoni]

That consumption level (300 ml per day) is very high for that size tank, and I suspect a lot of the supplement is precipitating and not making it into the tank. You might want to dose into the display, and cut the dose back a lot. Trying the recipe 2 might be useful, too, as it might precipitate less.

[tmc1313]

That consumption level (300 ml per day) is very high for that size tank, and I suspect a lot of the supplement is precipitating and not making it into the tank. You might want to dose into the display, and cut the dose back a lot. Trying the recipe 2 might be useful, too, as it might precipitate less.

I did start dosing into the DT (upstairs), around 6 weeks ago. I also thought this would solve the problem, but my GFO/GAC is still clumping which is all the way down in the basement, far from my dosing pumps.

[bamf25]

I did start dosing into the DT (upstairs), around 6 weeks ago. I also thought this would solve the problem, but my GFO/GAC is still clumping which is all the way down in the basement, far from my dosing pumps.

What reactors are you using, and how much flow are you putting through them?

[tmc1313]

What reactors are you using, and how much flow are you putting through them?

I was using the dual BRS reactor with the MJ1200 pump (I would get clumping). I wanted to make my maintenance easier, so I switched to GFO pellets and started mixing it with my GAC. I now run this through a fluval G canister and just swap out the chemical cartridges. I do this every two to three weeks and I'm still getting clumping of the material.

[Reeferhead]

I was using the dual BRS reactor with the MJ1200 pump (I would get clumping). I wanted to make my maintenance easier, so I switched to GFO pellets and started mixing it with my GAC. I now run this through a fluval G canister and just swap out the chemical cartridges. I do this every two to three weeks and I'm still getting clumping of the material.

I tried many of the same things and I have the same reactor. Your dosing too much. When you dose too much one of the first places CaCO3 precipitates out is around your GFO. If I had to take a guess I would imagine your pump impellers and heaters are probably accumulating a fair amount of CaCO3 as well.

Recalibrate your dosing pumps. Test them to make sure you know their current flow rate, they tend to drift a bit over time. Then reduce your Ca and ALK dosing by 25-50% every week until the clumping stops.

[bamf25]

I discovered with the brs reactors that in the gfo reactor you must keep a sponge at the top portion of the reactor chamber (the outflow). What seems to happen in the gfo is that the fines collect in the plastic grating and clog it, then you stop tumbling. I know BRS says the sponges are optional with gfo, but the top one is not. You were using that spong ignor this post. lol

[jerpa]

A third voice for overdose. I would cut the dose and test your alkalinity every three days or so. I think daily testing can be misleading due to the inaccuracy of test kits. If its still at 9 cut it some more. At some point your alk will drop. Increase your dosing a little until you find the sweet spot. If your alk drops when you first cut the dose you will know to look elsewhere.

[dublo8]

Your either overdosing or dosing the alk and cal too close to one another allowing it to precipitate inside the reactor and you may be dosing too close to the reactor. I just came across the same issue. I cut back dosing by 50% and moved the outflow of the doser further down stream. Also on a side note. BRS has a new design for the reactor cartridges. I highly suggest them. GFO now tumbles all over instead of just one side and it allows more flow through, plus they are 100% clear vs. milky clear HTH.

[ostrow]

An alkalinity level that high will normally result in clumping. I would try gradually to reduce to 8 and that should help significantly. You should not find any negative consequences to your inhabitants by doing so.

[tmc1313]

Sounds good, I'm going to cut back on the dosing and see what happens. Thanks for the advice. I'll update later on to let you guys know how things worked out.

[Reeferhead]

An alkalinity level that high will normally result in clumping. I would try gradually to reduce to 8 and that should help significantly. You should not find any negative consequences to your inhabitants by doing so.

9dkh is not that high (that's actually what I try to maintain)... but our hobbyist's kits aren't very accurate either. ;)

[kgross]

Another suggestion switch to recipe 2, the lower pH causes much less precipitation.

[tmc1313]

Another suggestion switch to recipe 2, the lower pH causes much less precipitation.

Yes, I am thinking about that too, but then if I am dosing the right amount at the moment, using Recipe #2, I'll have to double the amount to maintain levels.

[kgross]

Yes you will have to recalibrate you dosing, but you will have a lot less precipitation.

[ostrow]

Also be sure it is all tumbling, not just pushing brought one side. Geo reactors by far have the best flow-through

[mginn]

I agree with overdosing as well. Had the same exact problems and before long all your pumps will seize up as well. BRS has suggested dosing rates listed on their two part recipe website to try as a starting point and slowly adjust over time.